Central Heating issue

[gra001]

I have two motorised valves on the system (close to the pump). Just a few questions:
1. Does one control the heating and the other hot water?
2. Buzzing coming from one and boiler not firing up. Took cover off and although I didn`t do anything else boiler fired and rads hot.
3. I`m assuming I need to replace the synchronous motor (?) so have been out and purchased, Honeywell compatible. Two wires coming from motor, do I need to be careful how I rewire?....thanks.

[Ferg]

1. Yes.
2. You didn't open it manually? Then I doubt it's the motor, more likely just worn and sticking.
3. The synchron motor wires can be connected either way around. Turn the power off, obviously!

[gra001]

Ferg said:

1. Yes.
2. You didn't open it manually? Then I doubt it's the motor, more likely just worn and sticking.
3. The synchron motor wires can be connected either way around. Turn the power off, obviously!

Thanks Ferg, the heating has now been OK all afternoon. You say "just worn and sticking"...you mean the motor or something else?

Edited by gra001 on Monday 14th February 17:15

[Ferg]

Could be a lot of things. The valve itself, the little 'rack' that the motor pinion moves, a combination of both or the bearing surfaces where the plastic bit goes through the galvanised baseplate. Might be worth a blast of WD-40 in the bottom of the valve, beneath that plate that the motor mounts to.

[gra001]

Ferg said:

Could be a lot of things. The valve itself, the little 'rack' that the motor pinion moves, a combination of both or the bearing surfaces where the plastic bit goes through the galvanised baseplate. Might be worth a blast of WD-40 in the bottom of the valve, beneath that plate that the motor mounts to.

Thanks again, I`ll wait and see what materialises.

[gra001]

OK Ferg. I turned heating off, left for 15 mins and then turned on again......boiler didn`t fire. Replaced motor and now firing so hopefully all good. Ta!