wiring checking

[dotto]

Hi all.
Conventional indirect system. No HW, CH OK. Three port motorised valve. I suspect the valve needs replacing, but, before i touch anything, i would like to check the wiring connections first, since my room stat is playing funny as well, in the sense that when i manually turn the wall stat to zero, the CH does not switch off. Can you please tell me what you check and how you check the wiring connections with a multimeter? And also, at the first sight, i can you tell if a three port valve is mid-position or just diverter??
Thank you.

 

[wilhelm]

trace the wire from the valve to wiring centre. undo cover on wiring centre....leave power on and stand in bucket of water whilst doing this.
....if you want, but may as well turn off ch fused spur.
anyway if there are three wires within said cable..its a diverter . if 5 its mid pos.

sounds like your valve head is knadgered. what make is it? shiny metal box or white plastic?

 

[dotto]

trace the wire from the valve to wiring centre. undo cover on wiring centre....leave power on and stand in bucket of water whilst doing this.
....if you want, but may as well turn off ch fused spur.
anyway if there are three wires within said cable..its a diverter . if 5 its mid pos.

sounds like your valve head is knadgered. what make is it? shiny metal box or white plastic?

Shiny metal. As i said, i have also probs with CH.if i turn off CH via Wall stat,it does not switch off. The only way of switching it off is via the programmer.How can i check with multimeter if all connections to valve, room stat and pump are OK?? Please, step by step instruction> Thank u.

 

[wilhelm]

well remove roomstat cover and ....with power off. avo set to ohms or buzzer, check by tuning the knob, it is actually swithching? on and off.

 

[aaronhoughton1978]

It sounds as if your motorised valve is stuck open in the central heating position. With the programmer set to hot water only you should have power to the cylinder stat, and from that to the same connection as the orange from the valve. When you turn the cylinder stat down you should get power on the grey to the motorised valve. With the heating on at the programmer and the room stat turned up you should have power on the white wire, which is lost when the room stat is turned down.

If you have a honeywell valve, it may be worth removing the synchron motor, and seeing if the valve returns freely on it's spring. If this is the case then replacing the synchron motor should be sufficient.

If the valve is not a honeywell or does not return freely then the whole valve will probably need replacing

If the motorised valve is stuck in the central heating position then the boiler will fire to heat the hot water, but sending the heat to the radiators, thus never satisfying the cylinder stat

 

[dotto]

It sounds as if your motorised valve is stuck open in the central heating position. With the programmer set to hot water only you should have power to the cylinder stat, and from that to the same connection as the orange from the valve. When you turn the cylinder stat down you should get power on the grey to the motorised valve. With the heating on at the programmer and the room stat turned up you should have power on the white wire, which is lost when the room stat is turned down.

If you have a honeywell valve, it may be worth removing the synchron motor, and seeing if the valve returns freely on it's spring. If this is the case then replacing the synchron motor should be sufficient.

If the valve is not a honeywell or does not return freely then the whole valve will probably need replacing

If the motorised valve is stuck in the central heating position then the boiler will fire to heat the hot water, but sending the heat to the radiators, thus never satisfying the cylinder stat

Hi,and thanks 4 your reply. So you are saying that if i call 4 HW and the radiators go hot instead of HWcylinder,then i would know 4 sure that the valve is stuck in the HW port??

 

[ChrisR]

TRy:
http://content.honeywell.com/uk/homes/Catalogue/Sundial Plans/3.4 Y Plan.pdf

Wouldn't mind a fiver for every Y plan which has been wired wrongly since it was put in.
Most commonly, it's the HW OFF connections from the programmer and cylinder stat which go awry.

 

[dotto]

TRy:
http://content.honeywell.com/uk/homes/Catalogue/Sundial Plans/3.4 Y Plan.pdf

Wouldn't mind a fiver for every Y plan which has been wired wrongly since it was put in.
Most commonly, it's the HW OFF connections from the programmer and cylinder stat which go awry.

Thank u Chris