Question 1

Why is my furnace not working?

Accepted Answer

The most common reasons a furnace stops working in Maine: (1) tripped circuit breaker — check the electrical panel; (2) clogged air filter starving the system of airflow — causing the high-limit switch to trip; (3) failed igniter — the furnace tries to start but can't light; (4) faulty flame sensor — the burner lights but shuts off after a few seconds; (5) the thermostat is set incorrectly or has a dead battery. Start with the filter and thermostat. If those are fine, call RG Mechanical at (207) 441-5820.

Question 2

Why is my AC not cooling the house?

Accepted Answer

An AC that runs but doesn't cool usually has one of these problems: a clogged air filter blocking airflow, a frozen evaporator coil (often caused by the clogged filter), low refrigerant from a leak, a failed capacitor keeping the compressor from engaging, or a dirty outdoor condenser coil that can't shed heat. Start with the air filter. If that's clean, turn the system off and let it thaw for 2 hours, then restart. If it still won't cool — or the problem recurs — call us.

Question 3

Why is my heat pump not heating in winter?

Accepted Answer

Common causes: the mode is set to 'Cool' or 'Fan Only' instead of 'Heat' (check the remote or wall controller), the outdoor unit is buried in snow or ice and needs to be cleared, the air filter inside is clogged, the refrigerant charge is low, or the defrost board has failed (preventing the unit from clearing ice). If clearing snow and checking the mode setting doesn't help, call us — the fix usually requires a technician.

Question 4

Why is my furnace or HVAC making a loud noise?

Accepted Answer

Different sounds point to different problems: banging or popping at startup is usually ductwork expansion, but loud banging inside the unit suggests a cracked heat exchanger or failing blower wheel. Squealing or screeching indicates a worn blower motor belt or bearings. Rattling means a loose panel, screw, or debris. Rumbling from a boiler is scale buildup on the heat exchanger. Any loud or sudden new noise warrants a service call — especially banging or screeching, which indicate mechanical stress.

Question 5

Why is my heat pump or mini-split blowing cold air in heat mode?

Accepted Answer

Cold air in heat mode is almost always one of four things: low refrigerant from a slow leak (most common), a stuck reversing valve that's locking the system in cooling mode, a defrost cycle problem causing the system to shut down heating prematurely, or a failed compressor. The reversing valve and refrigerant issues require a licensed technician. Call (207) 441-5820 — this is one of our most common winter service calls.

Question 6

No heat in my house — what do I do right now?

Accepted Answer

Immediate steps: (1) Check your thermostat — make sure it's set to Heat, above the current room temp, and has working batteries; (2) Check the circuit breaker for your furnace or boiler; (3) Check that the emergency shutoff switch near the unit is ON; (4) For a boiler, press the reset button once only; (5) Set up electric space heaters near water pipes on exterior walls to prevent pipe damage while you wait; (6) Call RG Mechanical at (207) 441-5820 — we prioritize no-heat calls in winter.

Question 7

Why is my boiler making a banging or rumbling noise?

Accepted Answer

Banging and rumbling from a boiler — called 'kettling' — is almost always caused by scale (mineral deposits) built up on the heat exchanger. Water trapped in the scale layer superheats and flashes to steam, creating the sound. Mild kettling can be treated with a descaling flush. Severe or persistent kettling may indicate heat exchanger damage that warrants replacement. Don't ignore it — a damaged heat exchanger can crack and create a CO hazard.

Question 8

Why does my furnace smell like it's burning?

Accepted Answer

A brief burning smell at the start of the heating season (lasting 20–30 minutes) is normal dust burning off after sitting all summer. A burning smell that persists or smells like burning plastic, rubber, or electrical components is not normal. These smells indicate overheating, a failing blower motor, a wiring problem, or in the worst case, a cracked heat exchanger allowing exhaust gases to mix with room air. Turn the system off and call us if the smell is persistent or unusual.

Question 9

Why is my AC freezing up (ice on the unit or lines)?

Accepted Answer

Ice on your AC or refrigerant lines almost always means one of two things: restricted airflow from a clogged air filter or closed vents, or low refrigerant from a leak. Without enough airflow or refrigerant, the evaporator coil drops below 32°F and moisture in the air freezes on it. Turn the system to fan-only mode to thaw the ice (this takes 1–4 hours), then check and replace the filter. If it refreezes, you likely have a refrigerant leak — call us.

Question 10

Why does my heat pump ice up and not defrost?

Accepted Answer

A heat pump outdoor unit normally develops a light frost coating in cold weather, and it automatically goes into a defrost cycle every 30–90 minutes to clear it. If your unit is heavily iced and not defrosting — or stays frozen for hours — the defrost system has failed. Possible causes include a faulty defrost board, a bad defrost thermostat sensor, a malfunctioning reversing valve, or low refrigerant. A frozen outdoor unit with no defrost cycle is a service call, not a DIY fix.

Question 11

Why is water leaking from my mini-split indoor unit?

Accepted Answer

Water dripping from a mini-split indoor unit almost always means the condensate drain line is clogged. In cooling mode, mini-splits remove humidity from the air, and that water needs to drain out. When the drain line is blocked by algae or debris, water backs up and overflows. The fix is usually clearing or flushing the drain line — sometimes with a wet-vac or a bleach flush. If the drain is clear but it's still leaking, the unit may be low on refrigerant (causing the coil to freeze and thaw repeatedly).

Question 12

Why is my water heater making popping or rumbling sounds?

Accepted Answer

Popping and rumbling can indicate sediment buildup. A qualified diagnosis should consider tank condition and manufacturer flushing guidance; compare repair and replacement estimates if damage is suspected.

Question 13

How often should I have my HVAC system serviced?

Accepted Answer

Twice a year is the gold standard — heating systems in the fall (before the season starts) and cooling systems in the spring (before the heat hits). Heat pumps handle both heating and cooling, so they should be serviced twice a year as well. If you can only do one, prioritize fall service for heating safety before Maine winters set in.

Question 14

How long do HVAC systems typically last?

Accepted Answer

Service life varies by exact model, installation, maintenance, operating conditions, water quality where relevant, and parts availability. Check the equipment label and current manufacturer guidance, then evaluate present condition and repair history.

Question 15

Why are my heating or cooling bills suddenly higher?

Accepted Answer

Common causes in order of likelihood: clogged or dirty air filter, dirty evaporator or condenser coils, low refrigerant (heat pump or AC), failing capacitor causing the system to work harder, aging system that's lost efficiency, duct leaks, or poorly insulated pipes or ducts in unconditioned spaces. Start with the filter — it's free to check and often the culprit.

Question 16

What size HVAC system do I need for my home?

Accepted Answer

Bigger is not better with HVAC. An oversized system short-cycles — it turns on and off too frequently, which causes humidity problems, excessive wear, and higher energy bills. Proper sizing requires a Manual J load calculation that accounts for square footage, ceiling height, insulation, windows, air sealing, and climate zone. We perform this as part of every installation estimate.

Question 17

Should I repair or replace my HVAC system?

Accepted Answer

Do not rely on a fixed percentage or age rule. Compare safety, condition, repair history, parts availability, exact-model performance, and written repair and replacement estimates.

Question 18

What HVAC brands do you install?

Accepted Answer

We work with several top-tier manufacturers and recommend the best fit based on your home, budget, and goals. We don't push one brand — we push quality. We'll explain the tradeoffs between the systems we're recommending so you can make an informed decision.

Question 19

What should I ask before hiring an HVAC or plumbing contractor?

Accepted Answer

Ask about the proposed scope, equipment, permits, scheduling, and documentation relevant to your project. Confirm any regulated credentials or insurance directly before work begins.

Question 20

How quickly can you respond to an emergency?

Accepted Answer

Call (207) 441-5820 to discuss the problem and current availability. Scheduling depends on existing commitments, weather, parts, travel, and the service needed.

Question 21

Can I request an estimate?

Accepted Answer

Yes. Request an estimate for an installation or replacement. Repair visits may require diagnostic work; ask about current service and diagnostic charges when scheduling.

Question 22

What areas do you serve?

Accepted Answer

We serve Augusta and the surrounding Central Maine region. Contact us to confirm service in your specific town — our coverage area continues to grow.

Question 23

What happens during an HVAC tune-up?

Accepted Answer

A proper tune-up isn't just a visual check. For furnaces: we inspect and test the heat exchanger, igniter, burner, gas valve, blower motor, and flue. For boilers: burner inspection, heat exchanger check, pressure testing, water quality review, and safety valve test. For heat pumps and AC: refrigerant level check, coil cleaning, capacitor and contactor test, and airflow measurement. We document everything.

Question 24

How often should I change my air filter?

Accepted Answer

1-inch filters: every 1–3 months depending on household dust, pets, and occupancy. 4-inch media filters: every 6–12 months. HEPA filters: per manufacturer recommendation, typically every 12 months. A clogged filter is the single most common cause of HVAC problems — it starves the system of airflow and causes overheating, frozen coils, and premature failure.

Question 25

Can I skip a year of maintenance if the system seems fine?

Accepted Answer

This is the most common mistake homeowners make. HVAC systems can appear to be running fine while quietly degrading. Refrigerant leaks slowly over years. Heat exchangers develop hairline cracks. Capacitors weaken before they fail. By the time you notice a problem, significant damage is often already done. Annual service catches these issues at their cheapest point.

Question 26

What is a heat exchanger and why does it matter?

Accepted Answer

The heat exchanger separates combustion gases from household air. A suspected crack is a carbon-monoxide safety issue: stop using the equipment and follow emergency guidance. Inspection needs depend on equipment condition and manufacturer instructions, not age alone.

Question 27

Why does my HVAC system need to be cleaned?

Accepted Answer

Dust and debris can accumulate on evaporator coils, blower wheels, and drain pans, affecting airflow and operation. Follow the equipment manufacturer's inspection and cleaning guidance and address confirmed moisture or biological-growth concerns appropriately.

Question 28

What is an anode rod and does my water heater have one?

Accepted Answer

An anode rod is a metal rod inside many tank water heaters that helps protect the tank from corrosion. Inspection and replacement timing varies by model, water quality, and manufacturer instructions.

Question 29

Do mini-splits need to be cleaned professionally?

Accepted Answer

Mini-split indoor units can accumulate dust and debris on filters, coils, drain components, and blower wheels. Follow exact-model manufacturer cleaning instructions and seek service for persistent odor, drainage, airflow, or inaccessible internal buildup.

Question 30

What is a combustion analysis and do I need one?

Accepted Answer

A combustion analysis uses instruments to measure the efficiency and safety of your heating system's burner — checking flue gas temperature, CO levels, excess air, and efficiency percentage. It's the most accurate way to verify a furnace or boiler is burning fuel safely and efficiently. We include it in our annual heating system tune-ups.

Question 31

What's the difference between a heat pump and a mini-split?

Accepted Answer

Mini-splits are a type of heat pump — specifically a ductless heat pump system. A 'heat pump' typically refers to a ducted system that connects to existing ductwork (like a central AC but with heating too). A mini-split has individual indoor air handlers in each zone, requiring no ductwork. Both heat and cool using the same refrigerant-based process.

Question 32

Can a heat pump heat my home when it's -20°F in Maine?

Accepted Answer

Low-temperature capacity varies by exact indoor and outdoor model combination. Compare current manufacturer capacity tables at the project's design temperature with a load calculation, and include backup heat where the design requires it.

Question 33

How efficient is a heat pump compared to a furnace or boiler?

Accepted Answer

AFUE measures fuel converted to useful heat, while heat-pump COP measures heat delivered relative to electricity consumed. These educational ratings are not directly interchangeable savings guarantees; verify exact-model data at relevant temperatures and compare current energy rates and usage.

Question 34

What is the Efficiency Maine heat pump rebate?

Accepted Answer

Qualifying cold-climate heat pump projects may be eligible for Efficiency Maine incentives. Eligibility, amounts, paperwork, and processing change, so visit our rebates page and verify current requirements with Efficiency Maine before making a decision.

Question 35

How many mini-split zones (heads) do I need?

Accepted Answer

Each indoor air handler (head) serves one zone. For most homes, we see 1 head per floor working well for open-concept layouts, or 1 per room for more targeted comfort control. We assess your home's layout, insulation, and sun exposure to recommend the right number. Over-zoning adds cost; under-zoning leaves cold spots.

Question 36

How long does mini-split installation take?

Accepted Answer

A single-zone mini-split installation typically takes 4–8 hours. Multi-zone systems with multiple air handlers are usually a 1–2 day job. We handle the complete installation: outdoor unit placement, refrigerant line set routing, electrical connection, wall penetrations, and commissioning. No ductwork means minimal disruption to your home.

Question 37

Can I use a heat pump with my existing oil or gas boiler?

Accepted Answer

Absolutely — this is a common setup in Maine called a hybrid system. The heat pump handles the majority of heating loads efficiently, and the boiler kicks in as a backup during the coldest periods. This approach maximizes your efficiency Maine rebate while keeping the boiler as a safety net during the transition to heat pumps.

Question 38

Why is my mini-split blowing warm air in cooling mode?

Accepted Answer

Most common causes: the indoor filter is clogged (check and clean it), the system is in 'heat' mode rather than 'cool' mode, low refrigerant from a slow leak, or a dirty evaporator coil reducing heat transfer. If cleaning the filter and checking the mode setting doesn't resolve it, call us — low refrigerant requires a licensed technician to diagnose and correct.

Question 39

Why is ice forming on my heat pump or mini-split?

Accepted Answer

During heating mode in cold weather, the outdoor unit goes through a normal defrost cycle — brief frost is normal. Sustained ice buildup on the outdoor unit indicates a problem: low refrigerant, a faulty defrost board, poor airflow due to debris around the unit, or a refrigerant restriction. Ice on the indoor unit in cooling mode typically means a clogged filter or very low refrigerant. Either scenario needs professional attention.

Question 40

What's the difference between a boiler and a furnace?

Accepted Answer

A furnace heats air and distributes it through ductwork, while a boiler heats water for radiators, baseboards, or radiant tubing. Service life for either varies by model, installation, maintenance, conditions, and parts availability.

Question 41

How do I know when my boiler needs to be replaced?

Accepted Answer

Repeated repairs, unexplained energy-use changes, banging or rumbling, corrosion, leakage, pressure problems, and limited parts availability can justify a replacement comparison. Diagnosis and written estimates help establish the appropriate next step.

Question 42

What is boiler kettling and what causes it?

Accepted Answer

Kettling is the banging or rumbling sound a boiler makes when scale (mineral deposits) builds up on the heat exchanger. Water trapped in the scale layer superheats and flashes to steam, causing the sound. Mild kettling can be addressed with a system flush and descaling treatment. Severe cases indicate heat exchanger damage and may require boiler replacement.

Question 43

Why does my furnace smell like burning when it first turns on in the fall?

Accepted Answer

A brief burning smell at the start of the heating season — lasting 20–30 minutes — is normal. It's dust burning off the heat exchanger after sitting all summer. If the smell persists, smells like burning plastic or rubber, or occurs throughout the season, shut the system off and call us. Persistent smells can indicate overheating, a failing blower motor, or wiring problems.

Question 44

What does a cracked heat exchanger mean for my furnace?

Accepted Answer

A cracked heat exchanger is a serious safety issue. Do not run the furnace; follow carbon-monoxide emergency guidance and obtain qualified diagnosis plus written repair and replacement options.

Question 45

What's the difference between a 80% and 96% efficiency furnace?

Accepted Answer

AFUE is an educational rating describing how much fuel energy becomes useful heat. Condensing furnaces use a secondary heat exchanger and different venting. Verify the exact proposed model, venting requirements, and current manufacturer data; AFUE alone does not guarantee savings or payback.

Question 46

Can I convert from oil heat to a gas furnace or heat pump?

Accepted Answer

Converting from oil is increasingly popular as natural gas is not available everywhere in Maine, but heat pumps are. If you have natural gas available, a high-efficiency gas furnace is a strong option. If not, a cold-climate heat pump with the existing oil system as backup is a great hybrid approach. We assess your specific situation and fuel options during our estimate.

Question 47

What is a pressure relief valve on a boiler and why does it matter?

Accepted Answer

The pressure relief valve (PRV) is a safety device that automatically releases pressure if the boiler exceeds safe operating limits. A PRV that drips or discharges regularly indicates the system pressure is too high — typically a waterlogged expansion tank or a filling valve issue. Never cap or plug a PRV — it's your last line of defense against boiler failure. If yours is discharging, call us.

Question 48

How do I know when my central AC needs to be replaced?

Accepted Answer

Indicators include repeated refrigerant leaks, recurring repairs, limited parts or refrigerant availability, severe condition issues, or inability to maintain comfort despite correct sizing and operation. Compare diagnosis and written repair and replacement estimates.

Question 49

What is R-22 refrigerant and why does it matter?

Accepted Answer

R-22 is an ozone-depleting refrigerant whose US production and import ended under federal phaseout rules. For equipment using R-22, compare current refrigerant availability, leak diagnosis, condition, repair scope, and replacement estimates rather than assuming one financial outcome.

Question 50

Why is my AC freezing up (ice on the lines or unit)?

Accepted Answer

The two most common causes are: (1) restricted airflow from a clogged filter, closed vents, or dirty coil — without adequate airflow, the evaporator coil drops below freezing and ice forms; (2) low refrigerant from a leak. Turn the system to fan-only mode to thaw it, then check and replace the filter. If it refreezes, call us — low refrigerant needs professional diagnosis.

Question 51

Why is my AC running but not cooling the house?

Accepted Answer

Most likely causes: low refrigerant from a leak, dirty condenser coil (the outdoor unit can't reject heat if it's clogged with dirt), failed capacitor (system runs but compressor isn't engaging), restricted airflow from a dirty filter, or a system that's simply undersized for the home. Start with the filter, then call for a diagnostic if the issue persists.

Question 52

How often should I have my central AC serviced?

Accepted Answer

Once a year in spring, before the cooling season begins. The service includes coil cleaning, refrigerant level check, capacitor and contactor test, condensate drain flush, and airflow measurement. A clean, properly charged system uses significantly less electricity and is far less likely to fail on the hottest day of the year.

Question 53

What SEER rating should I look for in a new AC?

Accepted Answer

SEER2 is an educational seasonal cooling-efficiency rating. Verify current federal requirements and exact-model ratings through official and manufacturer sources, then compare design conditions, usage, and project cost without assuming a payback period.

Question 54

How do I know if my water heater needs to be replaced?

Accepted Answer

Warning signs include rusty or discolored water, unusual odor, rumbling or popping, leakage, reduced hot-water delivery, repeated repairs, corrosion, or unavailable parts. Evaluate condition and manufacturer guidance rather than age alone.

Question 55

Tank vs. tankless water heater — which is better?

Accepted Answer

Tankless units heat water on demand within rated capacity, while tank units store heated water. Compare demand, fuel or electrical capacity, venting, water quality, maintenance, exact-model data, installation scope, and a project-specific estimate.

Question 56

Why does my hot water smell like sulfur or rotten eggs?

Accepted Answer

This is caused by a failing or depleted anode rod. The anode rod interacts with sulfur-reducing bacteria in the water supply, producing hydrogen sulfide gas — the rotten egg smell. The fix is anode rod replacement. If the smell persists after replacement, a bacteria treatment (hydrogen peroxide flush) may be needed. This is a maintenance issue, not a reason to replace the heater unless the tank itself is corroded.

Question 57

What is a tankless water heater scale flush and do I need one in Maine?

Accepted Answer

Hard water can cause limescale inside a tankless heat exchanger. Descaling method and frequency depend on water quality and the exact manufacturer's instructions; use only approved procedures and materials.

Question 58

My water heater is making rumbling sounds — is that serious?

Accepted Answer

Rumbling or popping can indicate sediment buildup. Diagnosis should consider tank condition, leakage, water quality, manufacturer flushing guidance, and written repair or replacement estimates rather than age alone.

Question 59

Can I install a tankless water heater in place of my old tank?

Accepted Answer

Yes, but there are considerations. Tankless water heaters require higher gas flow rates (if gas) or significant electrical capacity (if electric). We'll assess your existing gas line size and electrical panel. In some cases, the gas line or electrical service needs upgrading — we factor this into our estimates so there are no surprises.

Question 60

What rebates are available for HVAC upgrades in Maine?

Accepted Answer

Qualifying HVAC projects may be eligible for state or federal incentives. Eligibility, amounts, and tax treatment change; visit our rebates page and confirm current program and tax details with official sources before relying on them.

Question 61

How much can I save on heating bills by switching to a heat pump?

Accepted Answer

Results depend on the home, existing system, exact equipment, design, weather, use, and current energy rates. Compare recent energy history with a load-based design and project-specific operating-cost analysis; savings are not guaranteed.

Question 62

What is HSPF2 and why does it matter for heat pumps?

Accepted Answer

HSPF2 is an educational seasonal heating-efficiency rating. Verify current program requirements and exact-model ratings through official and manufacturer sources. It does not by itself establish operating savings or service life.

Question 63

Does proper insulation affect my HVAC system's performance?

Accepted Answer

Even an efficient HVAC system can struggle in a poorly insulated or air-sealed home because it must run longer. Before upgrading a system, consider whether insulation, windows, or air sealing are limiting comfort; an energy assessment can help prioritize improvements.

Question 64

Should I get a programmable or smart thermostat?

Accepted Answer

Smart thermostats can provide scheduling, remote control, and geofencing where compatible. Cost, energy impact, and incentive eligibility vary; verify equipment compatibility, current official program details, and project-specific pricing.

HVAC Knowledge Base

Troubleshooting Problems

HVAC General

Maintenance & Filters

Heat Pumps & Mini-Splits

Boilers & Furnaces

Central AC & Cooling

Water Heaters

Efficiency & Rebates

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