Gloworm Betacom 24C combi pressure problem.

[dhb]

Hi folks, can anybody advise me regarding my GloWorm Betacom 24c condensing combi boiler please?

It is just over two years old and out of warranty and recently the boiler was drained to add a new radiator. Upon filling to 1.5 bar and firing up all seemed ok and I left the boiler in the hands of the tenant. He has contacted me to state the boiler wont fire up after he has had it running for a while.

The symptoms are when cold and upon first inspection are water pressure is close to 0bar and upon filling and pressurising to 1.5 bar the boiler will fire and run. After 5-10 mins the radiators get hot but the water pressure increases into the red zone (not sure but possibly 4-6bar) and water can be seen escaping outside from the overflow pipe. Am I correct in my assumption it is a flat or split expansion vessel? Nobody has tampered with the vessel valve so I am on the side that it is split.

Does anybody know if it is the expansion vessel and if it can be relaced without boiler removal?

Also because the tenant has a habit of tampering with the filling loop could overfilling and overpressurising the system cause the vessel to split?

Any assistance will be very much appreciated.
Cheers

 

[jtsplumbing]

Sounds like a expansion tank fault, it wont go to 4/6 bar the safety valve will lift aroung 3 bar, B4 you go to the expence of replacement, get the tanks checked , may just need rechargeing and a new safety valve. as for replaceing the tank, its more than likely to be boiler off wall !

 

[Simon F]

having to many radiators (you say its a flat, so probably not to many radiators??)
for the size of the expansion vessel or over pressurising the system will have the effect of causing extra strain on the expansion vessel and make it more prone to premature failure.
what pressure has the tenant been putting in??

any way as its a rented property you will have the details of a gas engineer due to needing an annual safety check, give him a call to get it sorted

 

[dhb]

having to many radiators (you say its a flat, so probably not to many radiators??)
for the size of the expansion vessel or over pressurising the system will have the effect of causing extra strain on the expansion vessel and make it more prone to premature failure.
what pressure has the tenant been putting in??

any way as its a rented property you will have the details of a gas engineer due to needing an annual safety check, give him a call to get it sorted

Thanks very much gents for taking the time to reply, I really appreciate it.

A gas engineer has been round and reported that draining the sysstem could have caused the expansion vessel to deflate and lose pressure so he has pumped it up and stated that the system is now running at a steady 2.4 bar with all 7 rads hot. He states that if the overflow pipoe contines to show a water discharge then the 'blow off' may need to be replaced and couold have been damaged when the tenant over pressurised the system. Sound about right??
Cheers guys

 

[Petefinny]

Its more ikely that he has used the blow off to drain the system and that muck or something has caused it to jam open and leak, weve all done it before but just a quick replacement should do the trick.

 

[dhb]

Its more ikely that he has used the blow off to drain the system and that muck or something has caused it to jam open and leak, weve all done it before but just a quick replacement should do the trick.

Thanks for your reply Pete. Just to clarify i drained the system via a ground floor rad drain off and filled it afterwards.

i was asking if it is possible the tenant could have damaged the blow off seal when he over pressurised it.

they dont seem that expensive to replace if that is the problem.

cheers gentlemen.