Vokera Unica Programer and Combi Stat Problems

[Stuartdjgolfprodunne]

I have a Vokera Unica 28HE combi boiler. This was fitted around 3 months ago and works fine.

This was originally fitted with an Iflo 24 Hour/7 Day time switch.

All worked perfectly until.............

I had my house rewired and at this time I decided to add a wall thermostat. I had a Drayton combi stat added and kept the original programmer.

My plumber can’t seem to understand why the system doesn’t work and I don’t no why it wont work either!

Basically the hot water is fine although the central heating will now stay on 24 hours a day. Even if the programmer is off the stat will still turn the heating on. My property is now too hot. Seems a waste of energy having the heating on when im not in the property but this is what the thermostat is doing. I thought the thermostat would save me cash but its now costing a fortune!

Can anyone help?

Thanks

 

[mikely]

Do the time switch and the thermostat independently turn the heating on? If so, they must be connected in parallel. The time clock and room stat contacts should be connected in series as shown in Section 8, Fig 40 of the Vokera Installation manual.

 

[Stuartdjgolfprodunne]

The time switch efectivly serves no purpose now as only the thermostat turns the heating on? Any ideas?

 

[mikely]

Have you asked the electrician who did the rewire how he connected the room stat/ time switch? He should have checked that it worked correctly.

If for some reason you are unable to connect the system as per Section 8, Fig 40, you could replace the room stat with a programmable stat which will make the time switch redundant.

 

[Stuartdjgolfprodunne]

Anymore thoughts?

Should these components work together ok?

 

[mikely]

Should these components work together ok?

Yes, when connected correctly. I'm assuming it's a wiring problem because you say it has not worked since the rewire. Has your plumber been able to check the wiring between the boiler, programmer and thermostat? Does the programmer appear to work i.e. click on and off?