No CH but Got HW

[holty69]

Hi

My CH is acting a little wierd and could do with some advice.

I have a honeywell 3 port valve. When I pop HW and CH on the lever is in the auto position and the rads remain cold. I can move the level to 'man open' but it springs back. If i hook the lever into 'man open' the rads will get hot.

I have changed the synchron motor but it seems to be the same.

Any ideas on what is could be? Should the lever be in the 'man open' postition if both the CH and HW are on? Or should it be there if CH is only on?

I really don't know what to do, I can get the rads on if I move the lever.

 

[ChrisR]

The lever is only for part-opening the valve for filling, not a direct indicator of the valve position.
First check the wiring is correct - all the wires have to be there!
Then take the head off and see if the spindle moves its 40 ish degrees freely.

Could also be a seized head, or maybe internal head wiring.

 

[holty69]

ok just done a test with the programmer and lever.

CH only - Lever in Auto position, when moved to Man Open it stays there. Rads Cold

HW Only - Lever in Auto position, when moved to Man Open is springs back. Water Hot

CH and HW - same as HW only

CH and HW - hooked to stay at Man Open - HW and Rads come on.

 

[holty69]

ChrisR - thanks for the reply.

When I took the metal cover off the valve, the wiring looks fine (and looks ok since i changed the syncron motor)

Not sure how to check the spindle - could you describe it to me?

 

[pannierstan]

You need to check if there is a demand from the C/H side of the the timer and do you have a room stat.

Basically the motor is normally the culprit but you have replaced it!
That means that the valve is not recieving a signal on the white wire which drives the motor across for heating

Unless you understand the wiring of the system and know how to use a multimeter then get someone who knows what they are doing.

Stan

 

[holty69]

Stan,

Cheers for the reply, I took a look at the programmer and its been wired correctly. I have a room stat and its switched up to 30 degrees.

Makes sense about the white wire. Think i will have to get someone in! I spoke to the previous owner of the house and he said that the CH was working a treat before he moved out (but then he would!)

Any more suggestions/ideas?

 

[ChrisR]

CH and HW - same as HW only

Obviously wrong

Could be that you have no wire on the "HW OFF" terminal in the programmer, and/or no wire on the "satisfied" terminal on the cylinder stat.

Wiring here - pump connection may be different
http://content.honeywell.com/uk/homes/Catalogue/Sundial Plans/3.4 Y Plan.pdf

 

[holty69]

Hi Chris

Thanks for that - it must be a wiring issue rather than a plumbing issue....

When i looked at the programmer wiring it looked ok.

I'll take a look at the Cylinder stat, not entirely sure what to look for - but i'll do my best

Thanks for the advice, been brilliant so far

 

[holty69]

When the HW and CH is on - where should the leaver on the valve be positioned?

 

[namsag]

If it is an existing system and had been working perfectly ok before it packed up the chances of it being a wiring fault is very remote. On 3 port mid position valves 7 out of ten no heat faults are synchron motors the other 3 are faulty circuit boards within the valve that has gone. So providing you have power going through the room stat your fault is in the valve and either the head or whole valve needs replacing. If on the other hand you have a heat store cylinder with a 3 port divertor valve with no heat and synchron is ok it could be the cylinder stat faulty not giving a satisfied signal valve to allow heating to come on...

 

[Steve__M]

Stan,

I spoke to the previous owner of the house and he said that the CH was working a treat before he moved out (but then he would!)

Any more suggestions/ideas?

This message is to offer my solidarity with you more than being advice.

I rented a house with the opposite problem (no hot water). The landlord said he'd never had a problem. Magically, whenever the engineer attended, it would start to work.

Eventually we twigged that the hot water didn't work when controlled by the timer, but did work when turned on to constant. Doh! When the landlord lived there he had the hot water switched on constantly which is why he'd never had a problem. It was fixed with a correction to the wiring.

So to completely rule out a wiring fault it might be worth trying with other combinations of switching on with timer on/off.