Honeywell st699 issue!!!

15 Jun 2010
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United Kingdom
Hello all just moved into my first house and I have encountered a honeywell st699 which won't play ball, neither of the change buttons on the timer won't work on any of the settings including clock setting so the timer reads 0.00 am. Also when you push one of the switches onto once or twice the unit goes crazy mad like it wants to electrify u the unit works on constant however would prefer to get the timer situation sorted asap
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Here's a link to the User Guide on Honeywell's website

It might be worth trying the Reset button on the front panel of the programmer; if that doesn't work for you, I think it's time to replace the programmer.

I've just replaced my ST699 with Honeywell's ST9400C - a much more flexible programmer with 7-day control, independent control of CH and DHW, and 3 on-off periods each day. Strangely, the retail price is about the same as a replacement ST699; but the ST9400 can be picked up on ebay for about £55 - see here

There is a comprehensive Wiring Guide on Honeywell's website which shows exactly which wires do what in your current programmer; and where to relocate them if changing to a ST9400C.

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