Boiler Leaking Water

A boiler losing water into a basement with wiring and stored goods around it should not be left running unattended, so call and describe where the water shows up.

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When this becomes an emergency

There is standing water on the slab under the boiler that keeps coming back after you mop it.
The pressure gauge sits above its normal band and creeps higher as the unit runs.
The overflow pipe near the floor stays wet between firings.
Rust has bloomed on a fitting that was clean last winter.

What a pro does

The vessel itself is rarely where the water is coming from. In the older houses stepped up along the river terraces, boilers have usually been repiped more than once, and the leak turns up at a relief valve, a pump seal, or an aging fitting rather than the boiler body, so the first job is following the water back to a single origin. Climbing pressure that keeps forcing the valve open normally means the expansion tank has lost its air cushion. Shutting off power and the feed valve is a reasonable move while you're waiting.

Frequently asked questions

Is the relief valve at fault when it drips?

Usually not. It opens because pressure asked it to, and the underlying cause is more often an expansion tank that has waterlogged.

Does hard water play a role in these leaks?

It does. Mineral deposits build at joints and fittings over the years, and the scale eventually opens a path for a slow weep to start.

Can a slow leak be left until the season ends?

It is a poor bet. Makeup water constantly refreshes the oxygen and minerals in the loop, and that accelerates corrosion inside the system.

What is worth doing before someone arrives?

Cutting power and closing the water feed to the boiler stops the leak from being resupplied and keeps water away from live electrical parts.

Boiler Leaking Water?

Get connected with a local pro now.

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