There is a constant leak outside the house that I have traces to a blue topped valve. I believe it is a pressure relief valve. Do I have to replace the whole valve or can this be replaced?
How do I make sure that it is the valve and not the pressure that is at fault?

Hi Raithatha:

First I need to know if this a pressure relief valve from a boiler or a temperature and pressure relief valve from a water heater? If from a water heater is this a gas or an electric water heater?

MARK

And next we would like to know if you have,
1) a sprinkler system connected to the house service?
2) a check valve or backflow preventer installed out near the water meter,
3) a expansion tank installed on the cold water supply on the water heater?
Let's hear back from you. Regards, Tom

Hi,

Thanks for your replies. The valveis on an ordinary central heating boiler which has an emersion coil to heat the water as an option (never used).

The property is a simple semi detached with no sprinklers. Not sure about a check valve or backflow preventer near the water meteer. I am not sure I would know one if I saw one! - sorry. There is an expansion tank installed. Does thid help?

Raithatha...

All helped.. yes.

Are you familiar with your boiler system... the shutoffs, valves, vents, etc.

Is this a forced water boiler (pump present) or a steam bolier? Can you tell me what the PRESSURE reading is on the boiler? There should be a gauge at front, or on top of boiler.

This issue is either related to a defective fill valve (pressure regulator valve) or could just be the pressure relief valve itself.

Sorry for all the questions... but now that we know it is a boiler we are closer than we were before.

Answer questions...

MARK