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Andrew Smith
Andrew Smith, Engineer
Category: UK Plumbing
Satisfied Customers: 3629
Experience:  Domestic Gas, Commercial Gas, LPG, Unvented Hot Water, Part P Electrical, Commercial Catering
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We have a sunvic tlx 6501 programmer to control our vaillant

Customer Question

We have a sunvic tlx 6501 programmer to control our vaillant boiler. Over the last couple of weeks the heating is coming on when we have set it to be off, e.g. at 1:30am or at random other times. If I set the sunvic to manual it works ok, but of course the heating is then on all the time. Do I need a new programmer?
Submitted: 1 year ago.
Category: UK Plumbing
Customer: replied 1 year ago.
I have had no reply at all to this question, so I trust I will not be charged this time.Regards,***** *****
Expert:  Andrew Smith replied 1 year ago.

More than likely a control problem.

Do you have a room thermostat and a motorised valve in the airing cupboard?

Customer: replied 1 year ago.
Hiya,No motorised valve and yes the thermostat is part of the programmer.Roy
Expert:  Andrew Smith replied 1 year ago.

A combi boiler then?

Which Vaillant is it?

Is it a wireless thermostat (with a receiver box under the boiler)?

Customer: replied 1 year ago.
a combi boiler. Vaillant 828, no box under boiler, thermostat hardwired.
Expert:  Andrew Smith replied 1 year ago.

Ok, I suggest you fully reset the timer as some of the times may be overlapping, this will let you set all the times agin from scratch and see if it works again.

Try this;

Customer: replied 1 year ago.
Tried that twice and no joy. Went to price a programmer and was advised to remove batteries for several minutes and start up again with programming times temperature settings etc. Seems to work ok now.
Expert:  Andrew Smith replied 1 year ago.

no problem.

I thought you had done that when you replaced the batteries?

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