Vokera Compact 28

[TeTsuo36]

Hi, seeking some advice if possible please for Vokera Compact 28.

The safety valve is diverting water to outside, at a pressure of 3.5 bar.
I disconnected the filler loop (flexible hose) as i thought it might be filling. It was not and pressure remained high.

I removed water from system at a downstairs radiator to 1 bar pressure and the water stopped coming from the outside pipe, but the pressure then went back up to 3.5 bar in around 10-15 minutes.

If i have the mains water or DHW valve turned off the pressure will remain at 1 bar. If i then turn on and run the central heating with DHW valve still turned off the pressure rises slowly to around 2 bar and stays there. If i turn on the DHW valve the pressure rises quickly (a few minutes) to 3.5 bar.

Both central heating and hot water are working, but likely many litres of water have been coming out from the safety valve to outside.

I have read the forum here as much as i can and it seems it could be a an EV or HEX issue maybe?

Can anyone please advise, as i couldn't find my exact problem.

Thanks in advance, Mark.

 

[boabcelt]

Unfortunately, it sounds like your heat exchanger is gubbed. There is a pinhole allowing mains water into the heating side of the hex. The only advice I can give you is to find a reputable RGI to carry out the repair. Sorry

 

[TeTsuo36]

Thanks for a quick response, i had a feeling it would be that, this boiler seems prone to this problem (when searching the net). Looks like about £300-350 or so fitted, if i source the part myself.

Thanks.

 

[Agile]

Or cheaper with a Vokera fixed price repair!

 

[alan999]

Hi
I'm going to one of these tomorrow with the same fault. I am pretty certain it is the plate heat exchanger letting water into the central heating system not the main heat exchanger.
Can someone let me know if my diagnosis is flawed. If not the repair should be somewhat cheaper.

 

[tonybhoy]

There's no plate hex on these mate.

 

[alan999]

Good point. My mistake.
Im looking at a Vokera Linea 28 not a Compact. I know the Linea range has one. Not much help for the original posting however.

 

[tonybhoy]

Or cheaper with a Vokera fixed price repair!

Vokera only gaurantee this HEX for a month Tony, you have to pay for a year's warranty (@ £360) on the boiler and for the FP to get the Hex gaurenteed for the whole year.

Fixed price repairfrom vokera is around the £170 mark.

The Hex to buy for us is £200 inc vat and a new boiler-Compact 28-will cost about £440 with two years warranty or the Sabre 28 at £409 but the warranty on those are a bit of a lottery as it depends on the sticker on the front of the boiler so it's either one or two years and all plus fitting of course.

 

[tonybhoy]

Good point. My mistake.
Im looking at a Vokera Linea 28 not a Compact. I know the Linea range has one. Not much help for the original posting however.

To check the plate on the Linea run a hot tap and keep an eye on the digital display and wait until the temp is up to about 55 degrees C then turn off the iso valve (cold main) under the boiler and if the temp display jumps up to about the 90 degree mark then the plate is blocked.

 

[boabcelt]

To check the plate on the Linea run a hot tap and keep an eye on the digital display and wait until the temp is up to about 55 degrees C then turn off the iso valve (cold main) under the boiler and if the temp display jumps up to about the 90 degree mark then the plate is blocked.[/quote]

Good tip Tony. I take it you've been to Vokera training in Maryhill? I was there a few years ago and the guys in there really knew their stuff.

 

[tonybhoy]

Good tip Tony. I take it you've been to Vokera training in Maryhill? I was there a few years ago and the guys in there really knew their stuff.

Thanks Boab, yeah I went to Maryhill but the flowmatics were the range of boilers at the time

Had one of these Lineas last year with a similar problem and got the tip from one of the Glasgow Vok tech guys at the time.

Personally I think those guys run the best tech line in the business.

 

[alan999]

Sorry TeTsuo36. I didnt mean to jump into your thread. Hope you get your boiler sorted.

Thanks for the advice tonybhoy. I'm not sure the plate hex is blocked on the Linea. The c/h pressure is rising with the filling loop isolated. Thats why I believe its perforated. A new one is just over £100. I dont want to fit one if its not necessary.

 

[tonybhoy]

Thanks for the advice tonybhoy. I'm not sure the plate hex is blocked on the Linea. The c/h pressure is rising with the filling loop isolated. Thats why I believe its perforated. A new one is just over £100. I dont want to fit one if its not necessary.

Dead easy to change it over mate, four screws I think all done from the front.

If you turn the mains (water) off to the boiler at the iso valve then the water pressure should stop rising, I would think.

 

[TeTsuo36]

No problems, would you mind me asking what the Vokera fixed price repair is please? A fixed labour cost for any repair job?

 

[tonybhoy]

No problems, would you mind me asking what the Vokera fixed price repair is please? A fixed labour cost for any repair job?

Depends where you are mate but it starts at £170 inc vat labour and the part for Glasgow however the Hex is only covered for a month under their terms and conditions (it's a water thing) however £360 gets you a year including the boiler covered for all main or three main components I believe.

Depending on the age of the boiler I would recommend that you replace it like for like (if you can get one where your are) which comes in at £439 incl two years warranty, vat, flue and mech clock plus fitting (allow £500ish).