Boiler Troubleshooting
Boiler Losing Pressure — Why It Happens & How We Fix It
A sealed hydronic system should maintain stable pressure. If your boiler pressure gauge reads low or drops frequently, something is allowing water to escape the system — and it needs to be found and fixed. RG Mechanical diagnoses boiler pressure loss throughout Central Maine.
What to Expect
Correct operating pressure for most systems: 12–18 PSI (cold)
Small leaks in system piping or at fittings
Failing pressure relief valve that opens too frequently
Air bleeder valves that are stuck open
Corroded or leaking coil in an indirect hot water heater
Internal heat exchanger leak (serious — may need replacement)
Frequently Asked Questions
My boiler keeps losing pressure and I have to keep adding water. What's wrong?
Your system has a leak somewhere — even if you can't see obvious water. We perform a pressure test to locate the source.
What pressure should my boiler run at?
Most residential systems operate at 12–18 PSI cold and 18–25 PSI when hot. Check your boiler's label for the specific range.
Can I add water to my boiler myself?
You can add water temporarily via the fill valve to restore pressure, but this is a temporary fix. The underlying leak must be found and repaired.
Is it dangerous to run a boiler at low pressure?
The boiler's low-pressure cutoff will prevent it from operating below a safe threshold. However, the reason for the pressure loss needs to be diagnosed and repaired.
Ready to get started?
Call us or request a project estimate. Contact RG Mechanical to confirm service availability for your community.
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