H37XL and Greenstar 12i - Can't get the heating zones to work!

[jcsawyer]

Hey folks!
I have been trying to get my heating up and running properly but I have had some trouble. I bought a new house this year and I have only just got to the point where I'd like to use the heating a bit.

The house has two honeywell thermostats (Picture attached) one upstairs one downstairs, presumably paired to heating group 1 and 2 respectively on the H37XL. However, the entire state of the heating since solely dependent on the thermostat upstairs.

If I set both groups to "on" the boiler only kicks in when the upstairs thermostat has the little flame icon. If the downstairs one is on nothing happens. Now I am not sure what the situation is but it is fairly frustrating, as many radiators don't have the turnable valve things (No clue what they are actually called). As the house was clearly designed to rely on the heating. Only the rooms have the valves fitted.

Does anyone have an idea what is going on here? The house is about 6 years old, so I have to assume these did in fact work at some point? Especially since the H37XL is labelled with "up" and "down".

The boiler is labeled as a "Greenstar 12i System mk IV" So I assume that is the boiler model?


Would be super grateful if anyone could lend me a hand here, or at least point me in the right direction. I did try and get someone to come take a look but no one is available or wanted an insane callout fee.

Thanks!

 

[Chuck]

The chain of command for your system (assuming it is correctly installed) is as follows: The H37XL talks to the thermostats. The thermostats talk the zone valves. The zone valves talk to the boiler and pump.

You seem to be saying that both zones work as expected but only when the upstairs thermostat is calling for heat, i.e. the downstairs thermostat can open and close its zone valve to allow hot water to circulate but not activate the boiler. If so, the problem could be the zone valve head, or the wiring from that zone valve back to the boiler.

All the voltages in this system are mains level so unless you have sufficient experience/training to undertake mains-voltage fault finding safely you'd be best off getting a heating engineer to sort you out. It should be an easy fix for someone who knows what they are doing. Get them to service the boiler at the same time to save a call-out fee.

 

[ShaunCorbs]

When you turn the downs stairs stat up eg flame icon on does the port valve where the cylinder moves eg you should have 3 port valves

One hot water
One downstairs
One upstairs

 

[jcsawyer]

The chain of command for your system (assuming it is correctly installed) is as follows: The H37XL talks to the thermostats. The thermostats talk the zone valves. The zone valves talk to the boiler and pump.

You seem to be saying that both zones work as expected but only when the upstairs thermostat is calling for heat, i.e. the downstairs thermostat can open and close its zone valve to allow hot water to circulate but not activate the boiler. If so, the problem could be the zone valve head, or the wiring from that zone valve back to the boiler.

All the voltages in this system are mains level so unless you have sufficient experience/training to undertake mains-voltage fault finding safely you'd be best off getting a heating engineer to sort you out. It should be an easy fix for someone who knows what they are doing. Get them to service the boiler at the same time to save a call-out fee.

Cheers for this! This was the kind of insight I was looking at. I am a PC and networks guy, have no idea about this stuff though!

Edit: If I were to call for a heating engineer what exactly would say to them? Also, do you have any idea what something like this would cost?

 

[jcsawyer]

When you turn the downs stairs stat up eg flame icon on does the port valve where the cylinder moves eg you should have 3 port valves

One hot water
One downstairs
One upstairs

Hey. I am not quite sure what you mean?

On the h37xl, there is upstairs, downstairs and hotwater. In the case they are all on they all have orange lights.

When both of them are orange for upstairs and downstairs and the heating is "on".

There are the following scenarios

• Upstairs thermostat calls for heat, downstairs does not = Boiler is on with its green light
• Upstairs thermostat calls for heat, downstairs calls for heat = Boiler is on with its green light
• Upstairs thermostat does not, downstairs calls for heat = Boiler is off, no light, no noise
• Both thermostats are at temperature = Boiler is off, no light, no noise

Hot water I haven't messed with as it just works!

 

[ShaunCorbs]

Best to call an engineer out and say your heatings not working downstairs