Hot water working, heating not. Help!!??

[wingate1975]

Hi
A couple of days ago our heating stopped coming on, yet the hot water is still fine.
I have checked the thermostat and timer, both seem fine.
Thought the pump must have given up but have realised the room thermostat doesn't 'click' when turning it up. The flame symbol shows, but doesn't start the system going.
Can anyone advise?
Is it likey to be the 3 way switch? Saw a couple of forum posts which suggested this may be the fault.
Many thanks

 

[plummerman]

Could be a few things buddy. Could be your timer not sending power, your thermostat not transferring power or plain and simple a motorised valve not turning. You really need to be ok with electrical fault finding to find real problem.
If you don't know about safely using a multimeter/ live electrical testing best you get someone in to.

Good luck

 

[wingate1975]

Hi
Thanks for your reply.
I can cope with that so any advice gratefully received.

 

[plummerman]

Ok, somewhere in the house usually side of the cylinder there will be a wiring centre.. Inside there will be about 30 wires dependent on what colours have been used. You need to find the ch call from the timer to prove power is being supplied, next you need to find the ch thermostat call wire to check power going to the stat.. Then make sure it's coming back from the stat to your zone valve. This is the easy bit depending on which valve you have?

You could just skip all that and prove power is being supplied by the other components by finding if call is live on the valve. That way it's the motor at fault if it doesn't activate.

What valve is it? Honeywell, seimens, Drayton. Is it a 2 port/3 port type valve? 3 port looks like a tee piece. 2 port is just a straight valve with a motor on top

Have a look here.. Pretty much the universal guide for wiring s plans, y-plans but this just uses honeywell products. Other manufactures use a plastic head instead of metal so don't have an earth wire

http://www.honeywelluk.com/downloads/Systems-Plans/

 

[wingate1975]

Thanks.
The valve has a boxed motor on top, but can't for the life of me remember if it is a straight, or T. Will check when I get back tonight.
Any quick ways to tell if it is the Valve?

 

[wingate1975]

Should probably say the pump has not been making any strange noises, so am thinking it isn't this. Also it can be turned by the screw head on the front.
There appears to be no power going to the boiler either when it should be on.

 

[45yearsagasman]

View media item 30391 View media item 38425Which one of these?

 

[plummerman]

All types of zone valves have a manual ( or fill/drain lever according to maker )

2 port has a permanent live, so flicking this switch will bring system on even if timer is off.. So you'd really need to fault find

A three port has different powers coming from different sources so again you'd need to know what's what. You can stick this in manual mode as well but it won't help you know what's at fault just get you some heat..

2 port will have 240vac on the grey wire at all times, even with timer off. The brown wire should get power (240v) when timer/stat are both on which will move the motor and put power on the orange wire.

A three port will have power on the grey when hot water is off so be careful, your looking for 240vac on the white wire if a honeywell valve is fitted ( this is your power from thermostat/timer.. If power there these are working and motor is at fault

 

[wingate1975]

Right. It's deffo a 3 way, but i can't move the switch to the other modes.
Actually, by removing it I have switched it to 'H', but now can't get the damn thing back on!
It's a Honeywell Mid Position Actuator???

 

[Armo74]

If you can put it in mid-position and put the hot water on you should get heating unless the valve is stuck in rest mode which by the sounds of it it is.

 

[wingate1975]

A bit of brute force and the house is warming up. The valve has pretty much seized. The motor is working fine. Can the valves be bought on their own, or do I have get the whole unit?

 

[wingate1975]

Sorry, back again.
Replaced the complete 3 way valve and the heating still isn't working when turned on.
However it comes on when the hot water comes on (when heating switched off). Not on its own.
Any more suggestions appreciated.