Boiler Problem

[annieigma]

Son has a boiler for the hot water etc. It has a pressure gauge, and if the pressure drops to a certain level the boiler does not work. I also have a boiler like this, and if the pressure drops i open a valve and watch the pressure rise on a dial, and it stays good for a few months. My sons one needs re-pressurising every day, any ideas why???
Thank you.

[SirOracle]

He has a leak somewhere in the system.

[Gizmonster]

Just to clarify what SirOracle has said - the leak may not necessarily be in the boiler itself - it's in the "system". It could be leaking from one of the many pipes, or even a radiator. It's more than likely to be a joint somewhere (a weak point), but not for definite ..... happy hunting ......

[237SJ]

Air is getting into the system from somewhere.

[buildersmate]

The favourite candidates are the pressure reliefs (there may be one or more than one), that leak when defective. They leak either into a waste pipe which goes to the outside of the dwelling (whence you can stop it dripping), or via a tundish that discharges into an internal drain. A tundish is a pipe with a bit cut away so you can spot the water passing by.
You can do some diagnosis yourself.
The other candidate is a leak in the pressure expansion cylinder.

[buildersmate]

No, not air getting in. Water getting out. Remember, these systems are pressurised.

[dekkypoo]

Yep it's a leak, look for damp patches or try 'sniffing' around the house to see if there's a "damp" smell, if you can't find an obvious problem you could get some Fernox leak sealer and put that in, I've used it a couple of times with total success.

[The Builder]

Have a plumber run a pressure test on the radiator circuit, Annie.
If no problem, then first choice is the expansion vessel, then the relief valves BM mentioned.

[annieigma]

Thanks all,
firstly, where would we put the ferminax into the system? and, as builder says, if the system is pressurised, wouldn.t a leak be obvious? Will get son to have a good look for leaks ( He did mention one of the rads was not getting hot, and was noisy) and go from there.

thank you.

[Tuvok]

The radior might need bleeding

[DaisyNonna]

I was told to bleed the radiator. Beware! Boiler packed up completely.

[The Builder]

Annie, a leak would only be obvious if ALL the pipework is visible.

Some of it will be out of sight :o(