Vokera excell SP80 - central heating came on even though it

[Sipsoo]

Hi Group,

I have a wierd problem and I hope someone canhelp.

The other day for no reason the central heating kicked in even though the timer for the heating was switched off and the central heating temprature control was turned off. I had to switch off the unit via the mode selector switch and now if I require hot water the heating comes back on.

Thanks in advance

Ken

 

[scatmanjohn]

Sounds like the Hot water microswitch is stuck on.

 

[Sipsoo]

Great thanks for the tip..

Ken

 

[Agile]

It could be that the diverter valve ( well actually the hydraulic actuator ) gland is tight and not allowing the fulcrum are to return to the rest position.

Usually follows the gland leaking as limescale deposits on the pin and guide.

Would have been noticed during a service!!!

Tony

 

[Sipsoo]

Looked at that lastnigt and it was working ok.

 

[Agile]

I am always worried when I hear someone has looked at something and thinks its OK.

If you have the skills to determine thats its working properly then I would have thought that you would have the skills to see what is not working properly.

At first sight it would seem that the DHW demand switch is faulty. Does it click when manually operated?

Is the fulcrum arm retracting enough to leave a gap on the switch?

Tony

 

[Sipsoo]

It was not me who looked at it but a qualified engineer (i'm not that stupid), he tested both DHW and central heating while I looked over his shoulder. The DHW is working but the heating comes on as well even though it is switched off.

Regards,

Ken

 

[Agile]

I dont know what "qualifications" he had but he does not seem very competent if he was unable to identify the cause of such a simple fault!

Tony

 

[Sipsoo]

Hi Tony,

I don't want to get into a slagging match over qualification but to lay it to rest. The gentleman is question is amply qualified and corgi registered and currently installing a system in the new Ritz hotel in London. The reason he did not 'find' the problem was that I called him out late lastnite and he is unsure of that type of appliance.

I will test the DHW microswitch tonite when I get home to see if there are any readings across the terminals.

Ken

 

[DP]

Workin at the Ritz mean zilch. He might be amply qualified to work on a large system but be totally out of his depth with your boiler. But all this is speculation on my part.

What your man needs to do is track back to see what is making a demand on the boiler.

To do this, he will first of all need to sit down with the boiler manual and read how the boiler works. The manual is very good.

The two answers you have to your query should resolve the problem (more than likely)

 

[Agile]

Hi Tony,
The gentleman is question is amply qualified and corgi registered and currently installing a system in the new Ritz hotel in London. The reason he did not 'find' the problem was that I called him out late lastnite and he is unsure of that type of appliance.

Ken

Its odd that someone from Newcastle has to travel all the way to London do a normal job! I would suggest he must be very desperate for work! After taking into account hotel costs I am sure that I can undercut him at only £350 per day!

Your Vokera is a very common model and any competent boiler engineer will repair them regularly and be very familiar with them. I saw one just this afternoon!

Tony