Hi All
Long time since I've been back to these forums and I have looked around for the answers but as yet with no luck.
I have just moved into a house with what I am assuming is a Y plan installation. It has a Honeywell 3-Port 40003916-003 valve, with Port B going to the Boiler, and Port A going to the Central Heating circuit. The Controller is a Horstmann Centaur Plus C27. It is programmed for separate times for the hot water to come on (just twice a day, morning and evening) and the central heating (morning, early afternoon - late evening).
During these times however, the central heating is not on (i.e. the radiators don't get hot and the pump doesn't run) unless the hot water is also on. When the CH is commanded on, either by the timed program or by pressing 'advance', the red light illuminates on the controller, and the motorised valve opens up with the lever being free all the way across the gate. it also moves in response to the thermostat being turned up or down. But there is no pump activity, no boiler light up, and thus no hot radiators. If I then turn the hot water on manually however (by pressing 'Boost' on the controller, or it just turns on by timed program), the pump and boiler both fire up and the rads get hot (as well as the hot water heating up.)
So from the outside it would appear that the valve is being commanded to the correct position by the Central heating controller, but it doesn't result in pump activation or boiler light up.
I had read somewhere that the controller could accidentally be commissioned to gravity type system, but if this was the case, the controller would not then show separate time programs for central heating and hot water.
I contacted the previous owners and they said they always had the hot water running 24 hours a day (!) and the central heating was always on, just controlled by the thermostat, so they have never known it operate any other way.
In a few weeks I am getting British Gas to install a Hive system which I am guessing will result in ripping out the old controller and wiring to the valves / motor anyway. But I would like to make sure the bones of the system are working first, so that the engineer isn't left chasing his tail with what might be a fault elsewhere. Any ideas what the fault could be?
Thanks a lot, Derek
Long time since I've been back to these forums and I have looked around for the answers but as yet with no luck.
I have just moved into a house with what I am assuming is a Y plan installation. It has a Honeywell 3-Port 40003916-003 valve, with Port B going to the Boiler, and Port A going to the Central Heating circuit. The Controller is a Horstmann Centaur Plus C27. It is programmed for separate times for the hot water to come on (just twice a day, morning and evening) and the central heating (morning, early afternoon - late evening).
During these times however, the central heating is not on (i.e. the radiators don't get hot and the pump doesn't run) unless the hot water is also on. When the CH is commanded on, either by the timed program or by pressing 'advance', the red light illuminates on the controller, and the motorised valve opens up with the lever being free all the way across the gate. it also moves in response to the thermostat being turned up or down. But there is no pump activity, no boiler light up, and thus no hot radiators. If I then turn the hot water on manually however (by pressing 'Boost' on the controller, or it just turns on by timed program), the pump and boiler both fire up and the rads get hot (as well as the hot water heating up.)
So from the outside it would appear that the valve is being commanded to the correct position by the Central heating controller, but it doesn't result in pump activation or boiler light up.
I had read somewhere that the controller could accidentally be commissioned to gravity type system, but if this was the case, the controller would not then show separate time programs for central heating and hot water.
I contacted the previous owners and they said they always had the hot water running 24 hours a day (!) and the central heating was always on, just controlled by the thermostat, so they have never known it operate any other way.
In a few weeks I am getting British Gas to install a Hive system which I am guessing will result in ripping out the old controller and wiring to the valves / motor anyway. But I would like to make sure the bones of the system are working first, so that the engineer isn't left chasing his tail with what might be a fault elsewhere. Any ideas what the fault could be?
Thanks a lot, Derek