Bad Drayton mid position valve? - No CH !!!!

[skywatch99]

I woke up last week to the sockets not working in the house, reset the rcd and all was fine......for 2 days.

Then it happened again. This time I traced a burning smell to the airing cupboard. It was coming from the 3 port mid position valve (a drayton 670H340-30L0).

Inside the valve resistor R1 was charred but showing 2K7 on a meter, is this the correct value? What would cause this to happen? (Drayton refuse to tell me the value of this component - awful customer service). It seems that the neutral connection to the valve had never been screwed down and was loose. R2 on the board is OK at 67K.

The valve works and so does the HW and CH, but the RCD still trips occasionally and today would not reset until the boiler power had been removed. Restoring boiler power does not cause an RCD trip!

The synchron motor measures 2K6 across it's windings and infinity from the windings to the case, so not likley to have earth leakage current there.

I disconnected the m/p valve and all is well, but no CH!
Can I temporarily connect a live to where the m/p orange wire connects into the distribution to 'enable' the CH from the boiler?

Can anyone help me with this please?

Andrew

 

[flameport]

In the wiring box:
1. disconnect the wires to the valve, making a note of which colour was connected where.
2. use a short piece of wire to link the terminals where the grey and orange wires were connected

Set the valve lever to manual

System will now function and the hot water programmer/timer will switch the whole lot on/off.

Then buy a new actuator head for the valve, remove the temporary link and wire in the new actuator in the same way the old one was.

 

[seco services]

Can I temporarily connect a live to where the m/p orange wire connects into the distribution to 'enable' the CH from the boiler?

If you've disconnected the valve etc you can bypass the valve and connect a wire straight from the white wire terminal to the orange wire terminal so the heating will still be controlled by your stat but you'll have to manually put the valve in ch position.

 

[skywatch99]

Thank you so much for the replies.

So is it White to Orange or Grey to Orange? I think White, but you guys seem to disagree!

I can only seem to get the mpv into HW or mid.

It is currently locked in mid.

Will this be OK?

Cheers!

Andrew

 

[skywatch99]

I eventually linked white to orange and all seems to be working again for now.

Heat goes to everything with valve locked in m/p, but that's better than nothing!

Thanks for the help, with the cold weather this week it'll be a relief!

Hope to have parts to fix m/p valve soon.

Thanks again!

Andrew