Heating problem Please Help =o(

[phoenix79]

Hi i recently had a fault with my programmer that controls my boiler for heating and my hot water storage.

I had the ACL Life style LP241 so i replaced it with a Sunvic 720XL the wiring diagrams are the same and it actually listed on the instructions that it is a direct replacement so i need not remove the plate on the wall simply click the new one in place of the old.

Job Done!

However now i do not get any heating only hot water, what i have found is that i can get heating if i set the programmer to hot water on and heating on, by doing so the 3 way valve moves to mid position thus heating radiators around the house. But once the tank thermo reaches temp it all shuts of including the heating to radiators.

I have tested the valve and when demand for heating is present it positions accordingly but the boiler and pump are in active?

I have checked and double checked wiring and i cannot see a fault the whole setup seems fine and since i haven't touched the wiring other than at the programmer im starting to reach the point of giving up.

Does anyone have any ideas??

Recap:

New programmer Sunvic 720XL
Suprima Potterton Boiler
Drayton thermostat in living room
Drayton thermostat to Tank

 

[spacethegas]

i'm no wiz on these, & im unfamiliar with the model. but is there a switch on the back of the new one you should move to the fully pumped position.

 

[phoenix79]

The back of the new programmer is set to pump fed. Still no joy =0(

 

[Rob]

Sounds as though you have no 'HW OFF'

What is the grey wire from the 3 port connected to. This should be live when the hw is off on stat or programmer.

Alternativley the 3 port may be faulty. After its opened for opened for Heating do you hear it 'click'?

Why was the clock replaced in the first place

 

[phoenix79]

the programmer failed as it stopped turning both the heating and the hot water on

 

[phoenix79]

The valve clicks into CH position when there is a call for heating but no responce from boiler or pump

 

[MANDATE]

It seems rob884 has it nailed.
If you can verify that the grey is live (with HW off) which is a requirement for the valve to move from mid position to the CH only position. And verify the valve does actually go to the CH only position, then the microswitch within the actuator head is faulty and preventing power being diverted out through the orange wire to light the boiler.
Mid position valves seem to have 3 problem areas, stiffish valve spindle offers too much resistance, motor already has to drive against a return spring.
A duff motor, which can't deal with last half of the 'range' against a fairly strong spring.
And the microswitch as stated.
It so happens I've experienced all these at various times.

 

[phoenix79]

If this is the case. Could i bridge from the grey to the orange skipping the microswitch, inorder to save my heating system until i can get a new valve fitted????

 

[namsag]

Recheck all connections , Has the HW wire came out the back plate or the wiring centre or even the cylinder stat,
Check that the terminal connection on backplate has not slipped down stopping the pin on the clock locatating into it

 

[phoenix79]

Hello again, right i checked everything and no wires are loose so i bit the bullet and decided to bridge the connection basically running a wire from the grey in its current terminal to the Orange in its terminal.

Guess what the CH on its own came on "Result" on thing is it doesn't seem to shut off by the thermostat i am assuming this is because i am bridging the circuit. I am sure that this is definitely a valve microswitch fault.

Anyone think different?????

 

[MANDATE]

I don't think you should be bridging from the grey, it will never shut off.
I did once consider bridging from the white wire, which is controlled by the room stat, then it would shut off. If you were to select CH only the grey would keep the motor energised and in the CH only position.
My idea was to put a switch in the bridge wire, so I could select HW with switch off or CH with switch on, but never to select HW and CH together.
I never did it cause the actuator head was delivered next morning.

 

[phoenix79]

Changed the valve today and im up and running with heat GRRRRRREAT! as Tony the Tiger would say.