Normal radiators connected to hot water circuit

[Arcadium]

I just bought a new house that comes with your regular combi boiler central heating system, and looking at the programmer (a Honeywell st9400) the previous owner marked the hot water side as "bedroom radiators" and the heating side as "bathroom radiator" and indeed it seems to work that way: if I turn on the hot water side on the programmer it does heat the room, and it heats the bathroom when I turn on the heating side.

The actual hot water works even if both are set to "off".

I would not be too disturbed by that if the thermostat that is in the hallway was still controlling the bedrooms but it seems that as it is now I can only turn on or off the bathroom with the stat, and there is no way for me to control the temperature of the bedrooms.

So I was wondering if it's possible to swap some wires on the programmer in order to either swap heating and "hot water" or to connect the stat to the "hot water" instead? I don't care if I can't select a precise temperature for the bathroom.

Thanks in advance!

 

[terryplumb]

You will need a central heating engineer to visit to survey your installation and establish what jiggery pokery is going on ,and give you a price to give you a properly functioning system.

 

[oldbuffer]

1. Are you sure you have a combi boiler? Make and model would be useful information.
2. What, if any, motorised valves do you have?
2a. None
2b. One x 3 port valve (inlet and two outlets)
2c. Two x 2 port valves (inlet and outlet).
3. Do you have a wiring centre? This is usually a white plastic box with the motorised valve(s) wires going in, together with thermostat and other wires.
4. Do you have a hot water cylinder?

 

[Arcadium]

1. Are you sure you have a combi boiler? Make and model would be useful information.
2. What, if any, motorised valves do you have?
2a. None
2b. One x 3 port valve (inlet and two outlets)
2c. Two x 2 port valves (inlet and outlet).
3. Do you have a wiring centre? This is usually a white plastic box with the motorised valve(s) wires going in, together with thermostat and other wires.
4. Do you have a hot water cylinder?

1. Pretty sure yes. It's a Glowworm Easicom 24.
2. I see two valves, so 2c I guess.
3. Yes, both cables of the motorized valves are connected to a white box
4. Not that I know of, at least I can't see any, and it's not mentioned in the home buyers survey.

I must probably add that this is happening on the 1st floor of the house, on the ground floor there is underfloor heating and thermostats that seem to work fine.

 

[Deleted member 267285]

It seems to me that whoever has installed it, has either used an existing programmer and used it for zoning or installed a twin channel programmer for zoning. You’ll have hot water as it’s a combi.

 

[Arcadium]

It seems to me that whoever has installed it, has either used an existing programmer and used it for zoning or installed a twin channel programmer for zoning. You’ll have hot water as it’s a combi.

I'm gonna check with the seller but it's probably it, thanks! Is there any way I can re-wire the stat to make it control the bedrooms (aka the "hot water")?

 

[Higgy28]

Sounds like the two valves have been wired in to a single zone + HW controller. You'll need a new controller with two heating zones ( or possibly the hot water side can just be disconnected and a new single zone controller can be added) and a new thermostat for the other zone

 

[Deleted member 267285]

I'm gonna check with the seller but it's probably it, thanks! Is there any way I can re-wire the stat to make it control the bedrooms (aka the "hot water")?

Just re-read your post. It would seem that a zone valve has failed, fix it, and then it’ll work as before.

 

[Arcadium]

Just re-read your post. It would seem that a zone valve has failed, fix it, and then it’ll work as before.

Ah yeah? The thing is, if I put the "hot water" side on continuous it turns on and when I turn it off I hear the valve closing, and the same thing happens when I do the same on the "heating" side, so I thought the valves were working as expected. Is there a way I can check if they're faulty?