Hi, new here and not sure where best to post a question about CH (leccy or plumber?) - moderators please move if necessary. Also I don't know the right terms - e.g. how to differentiate between electrical circuit and water circuit except by context? So apologies if my writing is confusing.
I had CH installed in a house where previously we were all-electric. So for HW we have an indirect system (the boiler heats the water in a cylinder which has immersion heater ports), plus two circuits for upstairs and downstairs radiators.
The three (water) circuits are teed off a single output from the boiler (which is a Vaillant EcoTec plus 630) and controlled by motorised 2-port valves.
I specified radiator thermostats as well as room thermostats (one downstairs, one upstairs) and I wanted a programmer with separate control of on and off times for each of the three circuits (HW, CH down, CH up); however the installer put in a Drayton LP522 which only caters for two separate circuits (Ch and HW). So it has too many controls - in reality we could use either the radiator stats or the room stats to control the system for comfort. The way we use it is to use the room stats as "on/off switches", and turn up and down the rad stats when we go into or come out of rooms. Hey ho. It works.
My question is this: how is the electrical system arranged so that the programmer can open and close the valves at the programmed times, and the room and cylinder stats can also control the heating? If the room stats were just in series with the programmer output to the motorised valves wouldn't they only be able to stop the valves from being operated, by interrupting the electric supply to the motor? It suggests to me that if the room is warm at the time when the programme should be turning the heating off, the programmer won't be able to shut off the circuit (or if the stat is "normally closed", the equivalent result would be that when the room is cold, the programmer won't be able to open the circuit when the system should be turning on).
I'd be glad to hear your collective insights into how this system should be wired, and any changes you might recommend. [edited for spelling]
I had CH installed in a house where previously we were all-electric. So for HW we have an indirect system (the boiler heats the water in a cylinder which has immersion heater ports), plus two circuits for upstairs and downstairs radiators.
The three (water) circuits are teed off a single output from the boiler (which is a Vaillant EcoTec plus 630) and controlled by motorised 2-port valves.
I specified radiator thermostats as well as room thermostats (one downstairs, one upstairs) and I wanted a programmer with separate control of on and off times for each of the three circuits (HW, CH down, CH up); however the installer put in a Drayton LP522 which only caters for two separate circuits (Ch and HW). So it has too many controls - in reality we could use either the radiator stats or the room stats to control the system for comfort. The way we use it is to use the room stats as "on/off switches", and turn up and down the rad stats when we go into or come out of rooms. Hey ho. It works.
My question is this: how is the electrical system arranged so that the programmer can open and close the valves at the programmed times, and the room and cylinder stats can also control the heating? If the room stats were just in series with the programmer output to the motorised valves wouldn't they only be able to stop the valves from being operated, by interrupting the electric supply to the motor? It suggests to me that if the room is warm at the time when the programme should be turning the heating off, the programmer won't be able to shut off the circuit (or if the stat is "normally closed", the equivalent result would be that when the room is cold, the programmer won't be able to open the circuit when the system should be turning on).
I'd be glad to hear your collective insights into how this system should be wired, and any changes you might recommend. [edited for spelling]