Central heating leak

[jjb1333]

Hi
I fear i may have a small leak in my system and have read about these leak sealers on the internet.
My question is do they really work and if so which is the best one ?

I have a baxi 105e and was losing pressure I called an engineer and he replaced the pressure diverter valve ,(i was losing water out of the pressure release pipe outside.
This seemed to do the trick , the boiler was refilled to one and a half bar pressure and the pressure has dropped point one of a bar in 24 hours
I rang the engineer and he said there may be a leak in the system..
Comments would be appreciated..

 

[HERTS P&D]

Yep, sounds like you have another leak.

Check all pipework leading to all radiators.

Andy

 

[ianmcd]

It sounds like your engineer replaced the pressure releif valve but if he didnt re-charge the expansion vessel at the same time then you will still have the same problem, get a small plastic bag or a balloon and put it over the outlet of the pressure releif pipe (should be outside) and see if you get any water in it over a few days, if you do then it is indeed the expansion vessel

 

[Agile]

If you have the instant version the expansion vessel regularly fails! So its important to check and repressurise it if necessary.

Boiler pressure varied by about 0.4 bar according to boiler/heating temperature and should not be thought to be any problem unless the pressure when everything is completely cold has fallen significantly.

The gauge can have some hysteresis!

Tony

 

[jjb1333]

Yes the expansion vessel was checked and re inflated to the correct pressure according to the handbook and i have checked the outside pressure relief pipe and it is now dry .

When the boiler is cold should the pressure valve remain on one and a half bar or does it fluctuate slightly

All the pipework around the rads is good and dry

The boiler is a combi by the way..

 

[Agile]

The indicated pressure can fluctuate because of hysteresis in the gauge!

That can be up to 0.3 bar or more!

Tony

 

[gas112]

Gauge on an instant always fluctuates about , Leave everything along for a few days and if it dont drop below one do not worry

 

[jjb1333]

Many thanks everyone.....
Its put my mind at ease i thought i would have to have all the floor up everywhere to try and find a leak....

The pressure gauge hasn,t dropped much (Just one digit) in the last 24 hours..