Vokera LINEA 24. Hot water works - Central Heating not working

[tony1951]

Hi,

Not a gas safe operator but seeking help with getting my sons boiler to work.

My youngest son just took possession of his first owner occupied house. It has been empty for two years and is fitted with a Vokera Linea 24 combi boiler and heating system.

The hot water system works fine.

On Saturday when we were checking the boiler before operating it, we checked the system pressure and it was right down at the zero position on the dial. We re-pressurised it to about 1.4bar. A lot of water went in. It took about two minutes to get up to pressure. Thinking about it now, I suspect that the heating system had probably been drained down while the place was empty after the owner died.

The hot water works fine, but the central heating does not operate at all. The CH temperature setting is set to high and the mode switch is set to hot water and heat. There are no error codes on the dial and the light is green.

There does not seem to be any room thermostat system in the house. I am assuming it can be run without them. The only wiring going into the boiler as far as I can see is the mains supply.

Thinking about it now, I am wondering if when the radiators have been drained down there may be some procedure to clear airlocks at the boiler. The boiler is installed on the first floor of the two story house, so it is at the highest point of the system.

Any USER level hints would be much appreciated.

Thanks

Tony

 

[joni os]

A service, to include a tightness test of all your gas pipework would be money well spent.
Did you bleed the rads after filling.

 

[jtsplumbing]

As above no one ever gets the Plumbing or Electrics checked B4 they move in, don't even think it's included in the survey .

 

[tony1951]

A service, to include a tightness test of all your gas pipework would be money well spent.
Did you bleed the rads after filling.

Thanks for your reply. No we didn't. It occurred to me this morning that there is probably a massive airlock in the boiler which is certainly at the highest point in the system. The hot water would naturally bleed itself out as the taps went on, but the heating would not be able to do that. There is probably a bleed on the boiler too, but it may not be an option unless Gas Safe. I expect our re-charging the system just created a big 1.4Bar air bubble up about where the pump and heat exchanger are.

When I was around there on saturday we just saw the boiler was right down on water pressure and opened the fill valve. I had npt then realised that the system was almost certainly drained while the place was empty. :1eye:

I will download the manuals and see if an end user can open a bleed on the boiler.

Thanks for the replies to you and the other chap.

 

[jtsplumbing]

Still a good idea to get a gas check & service done, also get inhibitor put into system.

 

[tony1951]

They called out a heating engineer yesterday and he diagnosed a faulty circuit board. I'm sceptical about that. An easy way to part people from their hard earned cash in my opinion. If circuit boards failed as often as some installers like to suggest, our cars and aircraft would be littering the roadsides and crash sites across the world.

 

[joni os]

Circuit boards in boilers are susceptible to heat and water, and designed against neither, so failure has to be considered. However, in your case, the absence of error codes and the fact you have hot water would make me equally sceptical. Has the engineer gone through a fault finding chart and diagnosed by elimination or has he done voltage and resistance tests on the pcb.

 

[tony1951]

Thanks for the reply.

I am not directly in touch with the boiler now and am relying on reports from my daughter in law. The chap fitted the new board yesterday and apparently water began leaking from 'a valve'. He has ordered a new valve which is being fitted today..... I am hoping the board was not doused with water while powered up!

Yes - the absence of fault codes or a dead system, and the presence of hot water make me very suspicious. I may be overly grumpy about this, but I've been around long enough to see this kind of thing a few times - mainly where young women are taken to the cleaners by garages and appliance technicians..... I do hope not.

 

[jtsplumbing]

if your not happy with what you have been told, call out the boiler manufacture for a fixed price repair, in some cases it works out cheaper

 

[tony1951]

Good tip - thanks JTSPlumbing.

It is working now my son says. Cost them more or less £400.