Vokera Linea 726 - Rising Pressure

[simkin911]

Boiler bought 20/12/06, installed in January 2007. Been fine but this week has developed a fault. When the CH comes on the pressure continues to raise to beyond 3-3.5 bar and then the system starts to reduce the pressure by emptying the water outside. Subsequently, the pressure drops significantly and develops an 04 code fault (low pressure). HW is fine - problem only occurs after switching on the heating. Vokera are still covering this with their bog standard 2 yr warranty (so parts and labour, I think are covered) but, having spoken to their helpline, they've suggested it actually only needs a service as the fault sounds like "no air in the expansion vessel". They could service it (at cost) in April for me! My own plumber thinks there could be a fault with a valve or pressure gauge and would fix at cost (parts & labour). Anyone have any idea of the cause? I'm a non-technical person but if there's a fault I'd rather not pay to repair if it's still under warranty ! Meanwhile.... no heating ! Thanks.

 

[Nixt]

Expansion vessel air charge pressure is the first thing to check and should be done so on each annual service (which is now overdue). Can't understand why your installer thinks valve or gauge faulty as they appear to be doing their job. You'll probably find any 2 year warranty is conditional on having it serviced at 12 months.

 

[simkin911]

Thanks Nixt. This was helpful - upon further questioning, my installer has declared he's unsure what exactly is wrong and doesn't usually repair or service these boilers. Almost back to square one but at least I won't be risking a time wasting exercise with the original installer trying to sort something without much knowledge or experience in this area. I'll get Vokera or some other engineer out to have a look. Thanks.

 

[des lumsdon]

if its not the expansion vessl or the filling loop passing then it most likely
is the domestic plate heat exchanger

 

[Nixt]

if its not the expansion vessl or the filling loop passing then it most likely
is the domestic plate heat exchanger

OP says problem only with runninng CH. Above will cause overnight or even permanent pressure rise.

OP - You should easily find an approved service agent if you are in Edinburgh.

 

[hav it]

check there is air in vessel, if not recharge.
if problem still there check for blockage most times it will be at fault.

who put the boiler in ?? was it flushed correctly.

 

[simkin911]

Thanks for the replies everyone - sorry for my delay in updating - been away working nearly 10 days. I spoke to Vokera - they are still covering the parts & labour until the end of the year. Had a BG engineer out - recharged expansion vessel, boiler worked again for 2 days then same problem - low pressure lockout overnight though my girlfriend didn't spot rising pressure.
Engineer returned again, replaced a "valve" which had the same result, system was fine for a couple of days and then this morning, lockout again.
I didn't see the engineer on either occasion as I've been away so my girlfriend has been organising it. This is really annoying !
Should I just get Vokera out? They originally said they wouldn't come out as they believed the problem was a servicing issue (inadequate air in expansion vessel) rather than a fault with the boiler. ps - boiler a fitted by a competent fitter who I have used several times in the last 10 yrs to install boilers every time I (frequently) move house without previous problem.

 

[simkin911]

Short update : boiler pressure is increasing from 1 bar to 2 bar now. However, is leaking water outside now at 1.5-2 bar. This, I think, must be why the boiler continues to shut down overnight due to lack of pressure. Calling Vokera today....

 

[Sloop]

check flexible pipe from exp/vessel to pump.sometimes this gets blocked and gives a false reading when recharging exp/vessel.