Central Heating Pressure Drop and Possible Methods of Deduction?

[Resurrection89]

Hi everyone, Im Mark, new to the forums, and definitely not a plumber. Lowly sparky here.

Basically, i have had a problem with my boiler losing pressure. Easy enough to refill etc, but the pressure drop occurences are becoming more frequent. I assume its due to a leak on the system but i cant for the life of me locate it. I have mentioned the issue to plumber friends of mine who seem less than enthusiastic about helping me out... which suggests this is a b***h of a job to locate and correct?

If anyone has any tips / pointers i would be most appreciative. No problem getting hands dirty, just need to know where to start?

Ta everyone?

Mark

 

[CES]

locate your PRV termination outside and put a bag over it, if it fills with water there's a problem with your expansion vessel, PRV or associated pipework.

 

[bob the plumber]

as above, also if its not leaking from the prv and the leak is not visable its quite likely to be a pipe under your ground floor which if it is leaking will not be seen

 

[fuzzy]

leak or blow off due to faulty blow off or incorrect pressure vessel pressure

 

[Alpha man]

What make boiler Mark?

 

[GQuigley67]

seems to be alot of pressure/expansion problems on the forum recently, like every 2nd post lol

have a look at your pressure when your heating is on, should be between 1/1.5bar when cold, and rise by about 0.5bar or there abouts once it has reached temperature, if it raises by more and raises quickly then that indicates there is expansion problems and you will have to get a gas engineer to rectify the problems, but if your system is expanding by only 0.5bar then that rules out expansion problems. I would assume the leak is under the ground floor as mentioned as if it was above it would have showed, adding some leak sealer into the system is also an option if its a small leak and can't be located.

 

[aido]

Would adding another expansion vessel in the hot press solve the problem?

 

[GQuigley67]

you need to know if it is expansion problems first, could be a leak, but an external expansion vessel on the return pipe as close the boiler as possible would be fine, PRV may need replaced though which if inside the boiler will require a gas engineer to remove it and replace it.

expansion vessel will have to be sized correctly though for the size of system.

 

[Resurrection89]

Hi all, thank you so much for taking time out to answer this query. Im sorry i havent been online, busy busy coming up to xmas. I will try the bag over PRV, but as GQuigley67 has pointed out, my boiler only raises by 0.5 bar. I dont get excessive pressure, simply the drop in pressure over the day or two my boiler is on, which according to other posts looks like a leak under floor. Looks like its time to crawl under the floor.... lol


@Alpha Man, the boiler is a Worcester Junior Boiler, am at work so cant get specifics from the unit. Its the one with the awful key system instead of a filling loop... grrr....


Appreciate the replies guys.... and have an awesome XMAS

 

[GasmanxxxR1]

Start looking for wet/damp patches

Bingo, theres your leak

 

[Resurrection89]

GasmanxxxR1 appreciate that that is the case, but i have no leaks above ground, and all pipework runs above concrete floor in about a foot and a half of crawl space. I will obviously attempt to locate the leak under floor but obviously when dealing in confined space which is generally already damp in parts due to weather ingress etc, it can be awkward. This is why i first posted, as i just assumed you plumbers would have magic methods to locate leaks, like we have magic ways to locate cable faults without removing plaster .

Just to note, this may be just insanity here, but there is one radiator in my house which sounds different to the others. It is full, and gets hot in all areas, but sounds more active, almost like an echo of the boiler noise when operating. All other radiators are silent when in use, so i will start by getting below the floor at this point and see if there is anything wrong.