I have just fitted a Sunvic select XL programmer but the system isnt working properly. I have checked (many times) and the wiring for the whole system is correct. the set up is a drayton mid way valve, a cylinder stat, a drayton digistat room stat, a baxi solo 3 boiler, and circulating pump.
the probelms is as follows:
when the programmer calls for HW only, the system works as it should - the midway valve is turned to hw only, and the cyl stat turns the boiler/ pump on appropriately.
When the programmer calls for CH only, the boiler & pump come on automatically regardless of what the room stat is registering and where the midway valve is set. this is controlable by the cyl stat - if this registers satisfied, then the boiler is on permanently, if the cyl stat = calling, then the CH system works as it should (eg the room stat controls the midway valve and boiler appropriately). When the boiler & pump are going at the wrong time, the room stat will still control the midway valve appropriately, although as room temperature rises, the stat will not turn the boiler and pump off.
so to simplify:-
CH on + CYL STAT satisfied = boiler & pump on regardless of any other settings (althoguh ROOM STAT will control midway valve when it calls)
CH on + CYL STAT calling = CH works appropriately
HW on only = works appropriately
HW and CH on = works appropriately until the CYL stat = satisfied, then see the above problem
I'm tending towards the Sunvic contoller being faulty at the moment, but if this screams anything obvious to anyone out there, please let me know. this is driving me MAD!
thanks in advance
++++++++++++++++++++++++++++++++++++++++
just wanted to add that I know the Cylinder stat should have nothing to do with the CH, but for some reason it has become linked with this part of the circuit.
the probelms is as follows:
when the programmer calls for HW only, the system works as it should - the midway valve is turned to hw only, and the cyl stat turns the boiler/ pump on appropriately.
When the programmer calls for CH only, the boiler & pump come on automatically regardless of what the room stat is registering and where the midway valve is set. this is controlable by the cyl stat - if this registers satisfied, then the boiler is on permanently, if the cyl stat = calling, then the CH system works as it should (eg the room stat controls the midway valve and boiler appropriately). When the boiler & pump are going at the wrong time, the room stat will still control the midway valve appropriately, although as room temperature rises, the stat will not turn the boiler and pump off.
so to simplify:-
CH on + CYL STAT satisfied = boiler & pump on regardless of any other settings (althoguh ROOM STAT will control midway valve when it calls)
CH on + CYL STAT calling = CH works appropriately
HW on only = works appropriately
HW and CH on = works appropriately until the CYL stat = satisfied, then see the above problem
I'm tending towards the Sunvic contoller being faulty at the moment, but if this screams anything obvious to anyone out there, please let me know. this is driving me MAD!
thanks in advance
++++++++++++++++++++++++++++++++++++++++
just wanted to add that I know the Cylinder stat should have nothing to do with the CH, but for some reason it has become linked with this part of the circuit.