Leak in Combi CH

[kevhky]

Hi, ive a leak in my CH system (Combi Boiler)

Been hunting everywhere for it but cant locate it, the flow/return leave the boiler then hit a T one pair go upstairs the other for downstairs, i was thinking maybe to help locate the leak to either cut off the supply to either upstairs or down then obviously im narrowing it down.

What do you think is the best way to do this, would cutting the 22mm pipe and fitting end caps to it or mayby fitting isolating valves, my pipes leave the boiler are 22mm then after about 4 metres they split to 8mm via diffuser

Any ideas suggestions would be great

Thanks

Kev

 

[fazedup71]

well how bad is the leak? are we talking instant pressure loss or over a few days? even a weeping compression fitting is enough to stop a system fairly quickly, as the water evaporates you don't see a wet patch, is the pipe work under a solid floor?

 

[kevhky]

Hi
The pressure is dropping to zero over 2 days from 1.5 bar, this has been going on for around 4 - 6 weeks, the floors are floorboards so i do have access, ive checked and cant see any leak or even signs of any leak, is it upstairs or downstairs thats what i really need to know thats why im thinking end capping one or the other to see if i still get pressure loss when one side is blocked off (although doing so will be pretty arkward and dont really want to cut into the pipework)

Kev

 

[fazedup71]

have you checked the PRV? and just out of interest what boiler is it?

 

[kevhky]

PRV checked and dry as sticks

Boiler is Vokera Maxin 24e

Installer Inst

http://vokera.co.uk/wp-content/uplo..._installation_and_servicing_-instructions.pdf


User Inst
http://www.vokera.co.uk/wp-content/uploads/2009/04/maxin_users_instructions.pdf

 

[fazedup71]

well a leak inside the boiler would also give you the same problem, i know all about that after lifting all the floor boards up in a house to then find out the heat exchanger was leaking!

Yes you could islolate the upstairs from the down but you back to square one if the problem continues, are you totally sure there are no signs of a leak? if you really cannot see anything i would get an RGI in and have the boiler checked

 

[Agile]

Voleras are very prone to internal leaks.

You need a good boiler engineer to inspect and repair.

Tony

 

[kevhky]

I had a boiler man out on Wed of this week who assures me that the boiler is not at fault, he said if boler was leaking id see it dripping from below and water would be visible on my kitchen worktop below it, he rekons im losing around 2 pints in two days of water, so also says if it were upstairs you would be able to see by signs on the ceiling so said it MUST be downstairs

Im going to lift again to double check.

The 8mm pipe to the rads is continuos from the diffuser so basicall more or less impossible to leak (i have checked) the diffuser i can see and check (no leaks)

Its got me puzzled

 

[fazedup71]

I say he is wrong there, I have seen leaks on Heat exchangers inside the combustion chamber, they never leaked on the kitchen work top, so might be well worth a second opinion from someone else

 

[kevhky]

So you think it could well possibly be the boiler at fault (heat exchanger) like i say i have checked and i cant definately see a leak

The boiler bloke who came out is from insurance through barclays, so do you think if i get them out again and tell them i want the heat exchanger replacing (i know though that he will say i aint that)

Are they expensive to buy and easy to fit ????

 

[fazedup71]

all am really saying is a second opinion might help, hey the guy could be spot on but i know from experience that not all leaks on a boiler will show as something visible that will drip from the appliance, I would expect to be able to find a leak like yours on pipe work fairly easily.





edited due to me not making any sense whatsoever

 

[kevhky]

I would expect to be able to find a leak like yours on pipe work fairly easy

Yeah same here, I

ve checked all the obvious places for leaks, if it were upstairs i should be able to see something

Could i possibly top up system to 1.5 bar then block pipe work (flow and return) from boiler then if pressure goes down id know boiler is def at fault

How could i get around this ?????

 

[fazedup71]

no that would be a bad idea, you need to maintain a minimum flow rate, even if your boiler had an internal bypass it would not cope with you isolating the flow and return pipe

 

[kevhky]

okay thats no problem

just found this on ebay (not far from where i live)


http://cgi.ebay.co.uk/VOKERA-DHW-HE...vr_id=&cguid=cff783291270a0e205427442ff32fc2a

Are they easy to fit

 

[fazedup71]

am i missing something here? just noticed you have exactly the same post 2 months ago when by the sounds of it the expansion vessel might have gone, you said in that post the boiler was hitting 3.5 bar!