Y Plan Advice Please

[rolyberkin]

I am probably being a complete numpty but I have a four zone heating system of which three of the zones and hot water are controlled by a couple of Honeywell ST9500C Two zone controllers.

I have a further two underfloor heating zones which a connected via a Danfoss FH WC underfloor heating controller via a Honeywell ST9100C, When I switch one of the wired thermostats supplying the Danfoss FH WC I hear the click of the relay but then get no power at the boiler and pump feeds.

My wife has stated that there is a cold snap coming and could I possibly fix it, the fuse in the controller is fine, I have power to the thermostats and switched live to the controller? Could the controller be knackered?

Any ideas welcomed as the Mrs has got the hump!

 

[davesparks]

What part of it is Y plan?

 

[davesparks]

Are you an electrician/apprentice/diyer?

 

[rolyberkin]

Are you an electrician/apprentice/diyer?

Previously worked for a DNO as a cable jointer 28 years ago and have had basic contracting training during my apprenticeship (putting plugs and lights in substations etc) Now working towards a career change as I can take early retirement in two years, have completed a 2365 L2 and most of L3, so in answer to your question would probably describe myself as a trainee as opposed to an apprentice or electrician.

There are three zone valves which are wired to the 9500c controllers, one for upstairs and downstairs heating, one for a separate office and one for hot water. I have rewired to add the separate office zone valve, I moved the underfloor heating from one side of one of the 9500c to the single 9100c controller (I take this to be the Y plan part of the system)

All the three zone valves work fine but the underfloor heating isn't working? Does this make sense?

 

[Leesparkykent]

Its not a Y plan. So there isn't a valve for the UFH?

 

[davesparks]

Previously worked for a DNO as a cable jointer 28 years ago and have had basic contracting training during my apprenticeship (putting plugs and lights in substations etc) Now working towards a career change as I can take early retirement in two years, have completed a 2365 L2 and most of L3, so in answer to your question would probably describe myself as a trainee as opposed to an apprentice or electrician.

There are three zone valves which are wired to the 9500c controllers, one for upstairs and downstairs heating, one for a separate office and one for hot water. I have rewired to add the separate office zone valve, I moved the underfloor heating from one side of one of the 9500c to the single 9100c controller (I take this to be the Y plan part of the system)

All the three zone valves work fine but the underfloor heating isn't working? Does this make sense?

Ok that makes sense as being a trainee, I'd recommend finding a local electrician to work with for a bit.

Your system isn't a Y plan whatever it is!

I've had too much cider to think through this one this evening, but I'd be happy to talk through it on the phone tomorrow if you like. PM me and I'll let you have my number.

 

[rolyberkin]

Its not a Y plan. So there isn't a valve for the UFH?

No zone valve on the UFH, it is controlled by the Danfoss control panel to which the actuators are connected, actuators are fitted to a manifold. There are two volt free outputs for the pump and boiler. If I put the controller on constant and switch the thermostat I hear a click at the control centre but get no power at the volt outputs (to the pump and boiler).

 

[Leesparkykent]

No zone valve on the UFH, it is controlled by the Danfoss control panel to which the actuators are connected, actuators are fitted to a manifold. There are two volt free outputs for the pump and boiler. If I put the controller on constant and switch the thermostat I hear a click at the control centre but get no power at the volt outputs (to the pump and boiler).

That's what I thought. Did this previously work or new install?

 

[sean_ork]

Can you bypass the stat and put a temp link across the stat terminals in the controller ?

Or just do a continuity check across the stat open/close terminals ?

Is the controller seeing the call for heat ?

 

[rolyberkin]

That's what I thought. Did this previously work or new install?

Sorry I obviously have four valves, three for heating zones and one for hot water!

It has all previously worked although the UFH was on one side of one of the two zone controllers, the wiring was awful (not done by me I hasten to add, it looked like a birds nest crammed into two back boxes!) whilst I was adding in the additional zone valve I tidied up all up the wiring putting it all into a wiring centre and moved the UFH to it's own controller. So my issue appears to me to be with the underfloor heating in isolation, everything else is working, I have wired the independent pump to the pump output of the wiring centre and a feed to the boiler. Could I have damaged the relays with back feed from the zoned heating? With everything else isolated there is no power at the output from the UFH control centre.

 

[rolyberkin]

Can you bypass the stat and put a temp link across the stat terminals in the controller ?

Or just do a continuity check across the stat open/close terminals ?

Is the controller seeing the call for heat ?

I think I have figured it out reading your post above, I think I have used the call for heat to feed the main panel and relays rather than a permanent live, the call for heat from the wall stats need to go into the PCB adjacent to the actuator valves! Will have a switch around tomorrow and hope I haven't damaged anything!?:-O

 

[sean_ork]

It's best to spend time working out how its all wired before you start experimenting, you'll not be able to find a exact schematic for a hybrid system such as yours - just break each component down and test if its really doing what it should be doing.

 

[rolyberkin]

It's best to spend time working out how its all wired before you start experimenting, you'll not be able to find a exact schematic for a hybrid system such as yours - just break each component down and test if its really doing what it should be doing.

Agreed, I am starting to doubt my last comment already, I will spend some time tomorrow taking it apart and putting it back together bit by bit. The zones are all working fine, I though the UFH would be the easy bit!?

 

[rolyberkin]

Re: Y Plan Advice Please - Solved

It's best to spend time working out how its all wired before you start experimenting, you'll not be able to find a exact schematic for a hybrid system such as yours - just break each component down and test if its really doing what it should be doing.

Just called Danfoss technical, the boiler and pump outputs are volt free so I was missing a link between the live feed and the relay blocks!

Thanks for all your help, will post a picture of my efforts in the trainee section later for comment

 

[sean_ork]

Happy Mrs again.

 

[rolyberkin]

Happy Mrs again.

Have told her she will be nice and toasty this evening!