Central Heating question

[Smoothound]

Basically it won't come on :D

Got hot water OK but when I turn up the Stat the 3 or 2 way valve is not opening. If I manually open it the pump kicks in and the rads get hot. I've been here before all too often and a replacement motor for the valve sorts it as a rule. Rather than pay a plumber to do it I'll go buy a motor and do it myself but I notice the motor has 5 wires connected but an older one still laying up in the loft has only 4 wires why is this as they have both worked! Also is it likely the motor has failed or do I need to replace the whole head?

[mark Taylor]

If it only has 4 wires Phil , it means it's double insulated and doesn't require an earth.
Is it a 2 or 3 way valve you have ?
As they work in completely different way.

Motor has 5 wires??
The syncron motor it's self should have only 2 wires, the complete actuator will have 5 wires
If it's a 3 way (y plan)
You will have
Yellow/ green = earth
Blue= neutral
Orange= boiler/pump
White= heating on
Grey = h/water off

If it's a 2 way (s or c plan)
You will have
Yellow/ green = earth
Blue = neutral
Brown = motor
Grey = common
Orange = switch live to boiler/ pump

Hope this helps

[Smoothound]

Ah right the old ones I have have plastic tops and only grey, blue, white and orange wires. So I guess they are double insulated and have no earth. Thew one on there that is not working is all metal made by honeywell but has 5 wires. Valve itself has 3 holes marked AB, A and B.

[inferno]

My heating has same problem, although landlord is responsible!

Be aware if the valve head keeps blowing it could be a sign of corrosion in the system blocking the valve and burning the moter out...

[Smoothound]

Mines been doing this for years and the actual valve is always free. appears after a bit of research the electronics on the valves are less than reliable ;)

[Sao]

I told you, that's a built in design feature of the system, gives them return business every couple of years :D

[Mart61]

I've had the same problem. I just buy the new motor for the valve and replace that. Tis a five minute job.

One question tho - have you "eased" the valve up at all? It's just that I had this self same problem when firing my heating up for the first time a couple of weeks ago. On removing the motor, spraying the valve with a bit of WD40 and spinning the valve around several times, it eased it up from being very stiff to dead smooth.

I guess that, after 6 months of inactivity, the valve stuck.

Give it a try...

:D

[Smoothound]

I'll try that tomorrow Mart but it felt pretty free when I used the manual switch on the side of the motorhead. I'll have my club hammer on standby as well :D

[joe.lel]

Happens here also!!!

Just give it a quick smack!! Its always sorted it out . LOL.

My view is that its just sticking a bit after not being on all summer!!!! LOL

[Magic919]

This guy fixed my faulty valve for a bit over a tenner and posted it back - [url=http://www.seered.co.uk/sunvic.htm]Sunvic motorised valve failures[/url]

Much cheaper than a new valv

[Smoothound]

[quote=Magic919;547491]This guy fixed my faulty valve for a bit over a tenner and posted it back - [url=http://www.seered.co.uk/sunvic.htm]Sunvic motorised valve failures[/url]

Much cheaper than a new valv[/quote]

I'll be ripping mine open later today to see if anything obvious has gone belly up ;)

[Smoothound]

Before I pull mine to bits, is there a method to test it is getting the right signal from the boiler/thermostat to make it switch on? If I turn up the thermostat nothing happens at the three way, if I manually push the slider across the pump starts and so the rads heat up. If I then turn down the Stat the slider does not straight away return to it's original position. I thought it was spring loaded so once the demand had gone it was returned by the spring?

[extreme 3d]

HI can you take the valve head off and look at the drive in the middle this is a 3 postion valve so if you turn on your room stat it should go one way. if you turn on hot water on at the same time it should go to mid position and if you leave hot water on and turn heating off it should go the other way if it does all this and not connected to pipe work then it will be the valve on pipe work .
any probs pm me might be able to talk you though changing it .

[Smoothound]

Right I've now swapped over the motor unit with a brand new one. Still not working properly :( It is now giving us both central heating and hot water but the central heating is coming on every time the hot water comes on :( So I've gone from no heating to almost permanent heating :hat: I can only now think that the actual valve is failing inside. It also seems very hard to move the manual control on the outside too :ack2:

[Mart61]

With the motor on top of the valve, the manual lever control will be stiff. You're fighting both the motor and the gearing.

If the valve is stiff to move with the motor removed, then perhaps the valve is sticking.

There is also the possibility that you wired it up incorrectly?