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bachippy · Joined: 28 May 2006 Posts: 32 Location: Kent

Please could you advise me on the following situation.

My system comprises Suprima 50 boiler (recently thoroughly checked by portterton engineer when replacing parts), Honeywell 4073 3 port valve, Honeywell room stat, Potterton EP3002 programmer, Honeywell cylinder stat, Grundfos pump and Honeywell frost stat.

The 3 way valve, room stat and programmer were new with the boiler parts and have been wired in by a qualified electrician according to the wiring diagrams using a Honeywell 10 way junction box, he has used new wiring for all the components thus rewiring the whole system as per the diagrams.

The electrician has spent 3 whole days checking and rechecking the wiring, looking at boiler wiring diagrams as well as the Sundial Y diagrams and the valves and programmers own ones. He is now at a total loss and I am just in despair.

The problems encountered include:-

Phantom boiler running, as if frost stat telling boiler it's too cold - hopefully now resolved, should know later, hopefully the boiler won't come on of it's own accord.

Radiators getting hot when only hot water is on - still unsolved. When hot water on the manual lever is in the auto position with resistance to being moved. When the CH is switched on the lever becomes loose with no resistance. When the CH is switched off the motor whirrs and the resistance returns.

Tonight when the programmer got to the set time to come on the boiler lights showed that it was not getting instructions, however when the room thermostat was turned right up to over 25C the boiler fired.
However when the programmer switched off the boiler kept going until the room stat was turned down.
Clearly this is no good if I want the programmer to come on to heat water early in the morning, when I'm asleep, as I'd have to be up to adjust the room stat to make the boiler light.
Even with the programmer switched off the boiler will fire up if the room thermostat is turned up.

He's convinced it must be a problem somewhere in the wiring but says he has run out of options and doesn't see how it can be wrong when it is exactly as the diagrams show.

Please help.

vince knight · Posted: Sun Jun 04, 2006 8:16 pm Post subject:

Hi
Sorry you have not had a reply earlier as I have been away.
I know over 70 electricians and out of them only about 4 understand heating controls let alone fault find on them.
It sound like a wiring fault but is very difficult to pin point online as could be anywhere.
Where abouts in Kent are you please.

Vince