Boiler control question - updating?

[D_Hailsham]

Disconnect the blue wire from terminal 2 and try again. You could also try connecting the red to T2 (leave blue disconnected) as that is what the Honeywell instructions show. T1 bypasses the switch; T2 goes via the switch.

If either of these stops the fuse blowing, there must be a problem inside the stat and it will be safe to change it for the Digistat. If it doesn't, we'll have to dig deeper.

PS I was wrong about the T6360C intended for aircon; it's the T4360C which does that.

Your suggestion about disconnecting the Stat and joining red to yellow is a good idea, but do it only if my tests above fail.

 

[Sirbendy]

Right. Just had a chap round who used to service the boiler in one of our old rented properties.

He's got the bermuda lit.

However, once he'd stopped chuckling at the wiring centre, there was a lot of "oh s&*t" going on with his multimeter..

Then he said "pump's gone". Took the wires out of it..tested again - "no, it hasn't. Pump's fine! Hmm.".

He's put the blame on the 3 port valve for popping the fuses. Coming out end of next week to service the Bermuda and fit a new 3 port valve (although he did say it was a removable head job).

I said the Bermuda had the landlord check passed in December - "means nothing, it's not a service or anything. The boiler is crying out for a service..".

On his sheet, he's put "3 way valve faulty, boiler service and universal thermocouple". Sound plausible? No idea on cost yet. Paid the £80 callout.

So, still using immersion for hot water..but heyho. It's lit!

 

[bengasman]

There is a damn good item under FAQ about central heating controls, and some more info here.

Click! -> Central Heating Controls

 

[Sirbendy]

Still waiting on a call back from the heating lot that looked on Friday to quote for work. Not impressed really, for a 3 way valve, and a service. Oh, mustn't forget the universal thermocouple.

So, nuts to it. Took the cover off the T6360C (with house power off), pinged out all 3 wires. Power on, new fuse in and the programmer, pump and boiler sprang to life.

Valve defaults to hot water, is that right? If I moved it over and locked it in place, the rads warmed up (a bit, definite airlocks there!). All works fine.

Power off again, fuse out again, connected red and yellow to 1 and 3, left blue on T2 off. Power back on again, all working great still.

Hot water - fine. Click the 6360, the valve clicks and groans it's way over to the rad position. Click 'stat off, it groans all the way back to hot water again.

Bish bosh, that was the issue! Nasty feeling that on/off on the 6360C has fused shut, shorting out the live to neutral. I'll heatshrink it to make it safe.

That leaves me with 2 wires, and I'm afraid in that case the T6360 is coming off the wall, and the digistat is going in place.

So...hopefully all happy here, and I'm going to be calling round tomorrow for prices for a boiler service, and hopefully get one done without waiting for an age.

Watch this space..heh..many, many thanks to all who suggested fixes here, you are truly invaluable.. "3 way valve at fault" my bum...i'd have been ££ worse off and still had the issue, i'm guessing!