weird 3 port valve heating behaviour

[needmorstuff]

well I have had 3 people out to my boiler now.. long story.

turned water off and ch is on but thermo not calling for heat and boiler fires up and rads get hot. whenever water goes off rads go on regardless of ch setting on controller or thermo setting. now I've set ch and water to off on controller and boiler is still on and rads getting hot.

if I have water and ch set to on on controller (but water is hot) and call for heat on thermo then the 3 way valve just clicks.

 

[needmorstuff]

see pics

 

[needmorstuff]

with both ch and water set to off on controller I have 240v on the orange/brown/brown for a few mins the boiler goes off and it drops to 0v.

I always have 240v on the grey/earth combo (why is there an earth jammed in with grey?) the earth is from the boiler tstat.

 

[D_Hailsham]

Deleted

 

[D_Hailsham]

If the system has worked OK previously, the chances are it's a motorized valve problem. The fault may be as simple as the valve sticking.

Turn off the electricity to the system (setting the timer to OFF is not enough).
The MV is now reset to HW only. The lever should be at the AUTO end of the slot.
Move the lever to the MAN end of the slot.
You should feel resistance and hear the gears whirring
If there is no resistance the valve is stuck open to CH
If resistance, release the lever
Lever should return to the AUTO end

Post results and make /model of MV

 

[needmorstuff]

If the system has worked OK previously, the chances are it's a motorized valve problem. The fault may be as simple as the valve sticking.

Turn off the electricity to the system (setting the timer to OFF is not enough).
The MV is now reset to HW only. The lever should be at the AUTO end of the slot.
Move the lever to the MAN end of the slot.
You should feel resistance and hear the gears whirring
If there is no resistance the valve is stuck open to CH
If resistance, release the lever
Lever should return to the AUTO end

Post results and make /model of MV

valve just been replaced, i have completely powered it off already a few time before to no avail. Its a honeywell 4073a, there is resistance and whiring.. and it does go back to auto.

 

[Echo the husky]

Well from the mass of wires it does appear logically to be wired correctly, even if it is untidy. The only thing I can come up with that would get your symptoms is the cylinder stat being wired wrong, or the valve is faulty.

Edit, if ch an hw are off when you restore the power the valve should stay closed (hw only position) the motor should not run.

If ch is the last to switch off, the pump/boiler should stop but the valve will stay fully open at ch only.

 

[needmorstuff]

Well from the mass of wires it does appear logically to be wired correctly, even if it is untidy. The only thing I can come up with that would get your symptoms is the cylinder stat being wired wrong, or the valve is faulty.

so if water goes off - cylinder stat being wired faulty would cause heating to ALWAYS come on?

any ideas on what wire/s is wrong and where they should go? I did look at some diagrams but with my day job being I.T I quickly felt out of my depth.

 

[Echo the husky]

http://wiki.diyfaq.org.uk/images/1/11/Y-Plan-Wiring.gif is one of the best diagrams, you will have to follow it through carefully. If I was there I could tell you in 2 minutes with a volt meter what the fault is.

I can only think the hot water off signal is ending up on the orange and firing the boiler and pump.

 

[picasso]

Worcester bosch ri and Honeywell 3 port ?

 

[Echo the husky]

Good thinking!

 

[needmorstuff]

it's an ideal ff240 and honeywell.

re hw off... on my controller there is no wire in the hw off... is that a problem? it's on one of the pics

 

[Echo the husky]

HW off is terminal 1 on the programmer. There is a blue wire in it which should (and appears to) go to the grey wire on the valve.

 

[needmorstuff]

the grey wire on the valve has a wire from the boiler thermostat... it's green/yellow..

 

[Echo the husky]

If by boiler you mean cylinder, then yes that's correct, the wire (which should have a red sleeve) should be connected to the hot water satisfied terminal in the stat (terminal 2)