Vokera Linea 28 endless faults - advice needed

[faultyvokera]

I have a Linea 28 - installed c.10 years ago. I've recently had a problem with the radiators getting hot even when the heating is switched off, and also the hot water not getting as hot as usual. Central heating was working normally.

A gas engineer has been working on it, but the problems seem to be escalating and I want to find out if this is usual.

First he fitted a new diverter valve.

The hot water was still not right - alternating between hot and cold. So he then fitted a new heat exchanger.

In the process of re-filling the system, the boiler overheated, and could not be reset as apparently the control/reset knob was not working.

He has fitted a new control knob, but now there is apparently a problem with the main circuit board and I am advised that this also needs replacing. I can't understand this as it was fine before he fitted the new knob.

I am therefore currently in a position with no heating or hot water (after having heating and lukewarm water at the start), and a bill that's increasing with every problem.

My questions:

- are all of these problems normal / feasible?
- is it possible that any of these problems has been caused by the gas engineer?
- could the circuit board problem be something simple like it's not been put back together properly?
- is anything else likely to be wrong?
- is the boiler worth fixing further?

Thanks for any advice you can give.

 

[nickso]

Pretty normal issues apart from the PCB issue. Weird things can happen though and it's not impossible that the PCB is faulty.

He may have damaged it, he may not have, no way to prove it really. He has to remove the PCB to change the control knob. Ask him to check he has put the control knob in correctly though.

 

[DP]

Wonder why a new diverter valve was fitted when the existing is perfectly serviceable. Regularly work on Vokeras but have yet to replace the diverter valve

HW alternating between hot and cold will happen to all boilers with plate heat exchangers cause being sedimented primary system (water going to radiators). Replacement boiler if fitted will end up doing the same thing if water quality remains the same

Boiler should not overheat. Control knobs do break but replacement is a lot better. He may not have fitted the control knobs correctly.

Anyone working on your boiler has to know how the boiler works and boiler needs to be serviced as described in the manual else side issues emerge to give you boiler issues you describe above.

 

[faultyvokera]

Thanks! So it sounds like I need to get him to check the fitting of the control/reset knob before coughing up for a new PCB?

Also, re overheating... he said it would be caused by air in the system when the boiler was re-started after fitting the heat exchanger. An 02 error code came up, but couldn't reset due to the faulty knob.

 

[faultyvokera]

Btw, re the diverter valve, both places I phoned about the original problem with the radiators getting hot when switched off said I would need a new one fitting, so I took it to be a kosher fix.... you live and learn!

 

[Agile]

Well fitting a new one will solve the problem.

But people like DP and I spend a little time to properly clean them out without needing to ever fit a new one!

Tony

 

[nickso]

Btw, re the diverter valve, both places I phoned about the original problem with the radiators getting hot when switched off said I would need a new one fitting, so I took it to be a kosher fix.... you live and learn!

I was assuming he had used a diverter kit which is cheap and the correct fix. Please tell me he didn't change the entire brass manifold?

 

[ianmcd]

the control knobs were very poor on these in the origional build but most have been replaced and the newer version is much more reliable, it is easy to test if the replacement is installed properly, turn the control knob to off and you should not have any display on the red digital display above the control knob,turn it to CH and HW and you should have a temp reading showing, turn to HW only and again you should have a reading , if at any time when you move the control knob and the display shows CO then the knob is fitted incorrectly, usually they are very stiff in not fitted right

 

[faultyvokera]

Thanks for all replies.

I finally got Vokera out to it on a fixed price and all is now working. Their engineer had never seen the circuit board blow like that before. That was replaced along with a few other minor bits and bobs, and apparently there was water in the motorised valve, which was probably the root of the PCB problem.

 

[Agile]

On most boiler designs water in the div motor would blow the fuse on the PCB which is typically 1.6 A.

Its always possible that a too high value had been fitted and the overcurrent had blown the tracks on the PCB.

Even so a correct 3A mains supply fuse would usually prevent that.

Tony