Hi Everyone,
Looking for some help please. I have a Heatslave 15/19 Oil boiler. When we came here it had just a Honeywell ST699 controller (no room thermostat).
We wanted to add some more control over the system, so I purchased a Honeywell CM927. I wired it with Live & Neutral from the boiler feed. I removed the jumper from Pin 2 & 3 of X2 in the Heatslave. Then connected A to pin 3 of X2 and then connected B to pin 2 of X2.
I left the ST699 in place, but set both CH & DHW to continuous. Obviously now the jumper has been removed, the CM927 should control the CH.
So, this morning my wife gets up and says.. damn it's hot in here.. and sure enough, the radiators are on. I go downstairs and the CM927 is set to off. The boiler also appears to be idle.
So what's gone on? Why did the CH run without control from the CM927? I have tried putting the ST699 CH control to off, but then the CM927 can't turn it on either.
Confused. Any help much appreciated.
Marc
Looking for some help please. I have a Heatslave 15/19 Oil boiler. When we came here it had just a Honeywell ST699 controller (no room thermostat).
We wanted to add some more control over the system, so I purchased a Honeywell CM927. I wired it with Live & Neutral from the boiler feed. I removed the jumper from Pin 2 & 3 of X2 in the Heatslave. Then connected A to pin 3 of X2 and then connected B to pin 2 of X2.
I left the ST699 in place, but set both CH & DHW to continuous. Obviously now the jumper has been removed, the CM927 should control the CH.
So, this morning my wife gets up and says.. damn it's hot in here.. and sure enough, the radiators are on. I go downstairs and the CM927 is set to off. The boiler also appears to be idle.
So what's gone on? Why did the CH run without control from the CM927? I have tried putting the ST699 CH control to off, but then the CM927 can't turn it on either.
Confused. Any help much appreciated.
Marc