Please help this Newbie with THERMOSTAT / HEATING problem

[STENDEC]

Hi

Could someone help me with the following urgent problem?

I disconnected myroom thermostat in my downstairs front room whilst decorating. The front of it was broken, so I bought a similar product replacement and fitted it. Unfortunately, no matter how I wire it ( I have done every conceivble combination, including following the diagram supplied) the circuit breaking fuse forthe stat keeps blowing. I think the longest it has stayed operational since the replacement is four days!

I have noticed that the entire wiring job from the Control panel to the room thermostat is very poor and probably would need complete replacement. However, it was working fine until the thermostat replacement, and as cost is a factor I would be happy to continue with the same system if I could fix or bypass the room thermostat.

Many of the radiators in my house are fitted with independent thermoststaic valves and so I was wondering if it was actually possible or easy to by pass the room temp thermostat and get operational heating again.

Any advice on how to do this would be great. I am not afraid to work with electrics and have previous wiring experience (lighting etc), just not to this extent.

If this is a job for a professional could you give me some idea of the expected cost of replacing and rewiring a control panel and room temp thermostat? I really cant afford to be ripped off.

Many thanks for helping this cold and depressed newbie!

 

[kevplumb]

putr a link in the boiler where the stat swich wiring is
boiler type/make /model ?

 

[STENDEC]

Thanks for the reply.

A link...I thought as much but aint too sure how to do it, as the wiring by whoever installed it (My guess not a pro) is a bit confusing and messy to say the least.

Control Panel is a very new digital siemens type (Though I note that the battery in this panel is missing, but I gather this only effects the memory in the event of power failure, and I always reset it after replacing the fuse. Thermo is a cheap wickes job a SUNVIC I think, but seems very similar to the original. Boiler is a reasonably modern POTTERTON PROFILE type.

I have now disconnected the wiring for the thermo from the control panel, so effectibvely its out the loop. A funny thing happened though. The hot water worked but the CH didnt....The pump wasnt circulating any water. I found a small box attached to some piping near the tank, which was marked as HONEYWELL and had a switch with AUTO and MANUAL on it. I tried switching it to MANUAL to see if this worked and the system blew again.

 

[kevplumb]

boiler type/make /model ?
__________________

 

[STENDEC]

Sorry, Havent got exact model numbers but the mufacturers are as stated in my second post above.

Just as an aside. I have apparently got FOUR wires into my room thermostat. One obvious live, one obvious neautral, a bare wire (I presume to be earth) anda afourth wire in a Yellow sleeve? My thermostat only has Three connection points marked up on it, so I connected the three sleeved wires to the apparently corresponding conncetion points but capped off with an insulating cap the bare wire.

There seems no other way of wiring the thermo up that makes the system work at all. Do you see this as the cause of the problem? What is the mysterious fourth wire for?

 

[ChrisR]

4 wires are switched live from thre programmer ch On, switched live out going back to the 3 port valve, earth and neutral. The Neutral is used in the stat for a tiny heater, connrected to SL out so the stat works a bit quicker.

Am Assuming you have one motorised valve with 3 pipes going to it(??) , so you have a Y plan system.
go here http://content.honeywell.com/uk/homes/catalogu.htm#SECTION 3- SUNDIAL PLANS and click Y plan. It's also possible you have C or S plan.

If someting(is it a mcb or an rcd??) is blowing but only after a while you have some damp or intermittent wiring somewhere we can't guide you with.

hth

 

[kevplumb]

bow
tugs forelock as he departs

 

[STENDEC]

THANKS!!! Definitely the Y system. Spot on.

However.... I reckon I am out of my depth with this now, so Will get a pro to rewire the whole thing. Seems that the system has gone wrong more than once then, if most of the original HONEYWELL components have been replaced with other manufactures?

Any idea of a rough cost and time to do this job by a pro, as there are some cowboys around in my town and I really cant afford to be ripped off. A fair price for a fair job is fine but I need to know what a fair price would be (Roughly of course)

Thank a million again (And I hope thats not what this job would cost)

 

[STENDEC]

Oops. Forgot to ask... I presume this could be a job for a Corgi plumber? Or would it be a Sparkies / standard plumbers realm?

 

[breezer]

get several quotes then you will know.

there are many things to consider
where you are
how easy it is to do
what has to be changed, etc etc

 

[STENDEC]

I'm in Swindon, S/west UK. I'll be basically requiirng a new control panel, room thermostat, hot water tank stat and associated wiring. Probably HONEYWELL or similar make as that was what was originally fiited.

I understand there will be variables but is there any chance of a ball park figure? ie, what would be extortionate in reality but just about believable enough to make me pay? Worst case scenario stuff.

I will not be getting a new boiler or tank, as these are ok enough to last the time I'm statying in this house. No matter what is said. Its just the electrical side of the system that will be replaced.

Thanks

 

[STENDEC]

No further advice?