Zone valve wiring

[Sid1968]

Forgive me if this in wrong topic

I have installed a underfloor heating on a central heating circuit with a combi boiler
Wired the wiring centre to the under floor heating and took switch live to the combi boiler all singin and dancin.
Now added a 2 port zone vlave to the heating circuit with a honeywell cm921 wireless programmable stat BD91 reciever

Trying to get my head around this to wire to the combi boiler
Can anyone help obvious live neutral earth to the connecter block. Bd91 live, neutral link out live to 3. This is wher i get stuck im sure its somethin simple
Also can i double up switch live from the zone valve to boiler with the underfloor heating SL??

 

[ericmark]

Not easy, there are all sorts of of ways to wire up, and it seems all down to boiler design. In general terms water to under floor heating is limited to 27°C, where most boilers want the return much hotter, normally around 60°C, so some method is required to do this, also modern boilers don't turn off/on but modulate i.e. flame height adjusts, so all controls also need to adjust, some boilers can take cool water return, but as to how a valve is slowly opened and closed is way beyond my knowledge.

With standard zone valves the thermostat works the valve, and micro switches inside the valve work the boiler, so any valve open and boiler fires up. But to do this you have to use the return water temperature to regulate the boiler, it is being used less and less and the WiFi TRV head is taking over.

In real terms zones in small houses don't work, in fact neither do the TRV heads, although in theory you can select times for each room so bedrooms not heated in day, and living rooms not heated at night or when out to work, the time for a standard radiator to heat a room with anti-hysteresis software built in is just too long.

Only way to get it to work is hot air, that hot air may be heated in a fan assisted radiator, but it is circulated and the radiator stays hot, just the fan switches to different speeds. With under floor heating the lag time from switch on to getting room to temperature is so long, can't really turn it on/off other than long term. Off for summer, on for winter can be done with a simple tap, it does not need motorised valves.

With a normal motorised valves you only have open/closed, there are specials, but way beyond DIY.

 

[Dan Robinson]

Also can i double up switch live from the zone valve to boiler with the underfloor heating SL??

Yes

neutral link out live to 3

No.

Can anyone help obvious live neutral earth to the connecter block

What do you think is the live?

Not easy, there are all sorts of of ways to wire up, and it seems all down to boiler design. In general terms water to under floor heating is limited to 27°C, where most boilers want the return much hotter, normally around 60°C, so some method is required to do this, also modern boilers don't turn off/on but modulate i.e. flame height adjusts, so all controls also need to adjust, some boilers can take cool water return, but as to how a valve is slowly opened and closed is way beyond my knowledge.

With standard zone valves the thermostat works the valve, and micro switches inside the valve work the boiler, so any valve open and boiler fires up. But to do this you have to use the return water temperature to regulate the boiler, it is being used less and less and the WiFi TRV head is taking over.

In real terms zones in small houses don't work, in fact neither do the TRV heads, although in theory you can select times for each room so bedrooms not heated in day, and living rooms not heated at night or when out to work, the time for a standard radiator to heat a room with anti-hysteresis software built in is just too long.

Only way to get it to work is hot air, that hot air may be heated in a fan assisted radiator, but it is circulated and the radiator stays hot, just the fan switches to different speeds. With under floor heating the lag time from switch on to getting room to temperature is so long, can't really turn it on/off other than long term. Off for summer, on for winter can be done with a simple tap, it does not need motorised valves.

With a normal motorised valves you only have open/closed, there are specials, but way beyond DIY.

Seriously... you don't know what you're talking about. Please stop giving advice to people.

 

[dilalio]

Yes



No.



What do you think is the live?





Seriously... you don't know what you're talking about. Please stop giving advice to people.

Tough day at school Dan?

 

[Dan Robinson]

.

A little frazzled , but we're a day ahead of schedule and the examiner for the final element wasn't due until Friday, so have a bonus office day. Gonna try and get the last part done in a day instead of two tomorrow and recover Monday as well