Frequently asked questions
What pressure should my boiler be at?
Most residential hot-water boilers run around 12–15 PSI cold and up to about 20–25 PSI hot. The relief valve is usually set to 30 PSI. Steam boilers run at very low pressure, often under 2 PSI. Check your boiler's manual for exact figures.
Why is my boiler pressure relief valve dripping?
Usually because system pressure is reaching about 30 PSI. A waterlogged expansion tank or a leaking fill valve is the common cause. Don't cap the valve; have the cause fixed.
How do I know if I have a steam or hot-water boiler?
Steam boilers have a sight glass showing the water level and a low-pressure gauge. Hot-water boilers have a combination pressure/temperature gauge, an expansion tank and a circulator pump.
Why are my radiators cold at the top?
On hot-water systems, trapped air collects at the top. Bleeding the radiator usually fixes it. If it keeps happening, the system may be drawing in air or the fill valve isn't maintaining pressure.
Why does my steam heat bang?
Water hammer happens when steam meets pooled condensate, usually because a pipe or radiator lost its pitch, the boiler water level is too high, or a vent is stuck.
How long do boilers last?
Cast-iron boilers often last 20–30 years or more with good maintenance; high-efficiency condensing boilers commonly run 15–20 years. Water quality and annual service make a big difference.
Should I add water to my boiler myself?
On a steam boiler, keeping the water level correct is a homeowner task, done per the manufacturer's directions. On hot-water systems, an automatic fill valve maintains pressure, and needing to add water often means there's a leak.
Do you service oil-fired boilers?
Yes. Providers in the network handle gas, oil and propane boilers. Oil boilers need annual nozzle, filter and combustion service.
Do you cover older city buildings?
Yes. Many providers in the network work on older steam systems in multi-family buildings. Find your state on the coverage map.
Who does the work?
An independent, licensed boiler and hydronics provider. Brassline is a referral service. See how it works.