Cylinder thermostat & C-PLAN question

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Berkshire
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Is a C PLAN allowed to be installed now under the Building Regs? As I believe the hot water AND htg need to be FULLY PUMPED.

Also, my main post- i believe the cylinder thermostat is not working - and not making the circuit - i have tested the terminals voltga eusing a multimeter safely, and there is power to the C terminal (when the programmer is on for HW) but nothing to the 1 terminal (which means the thermostat must be stuck) ... but reading the honeywell website fault finding guide, there is notes saying to remove terminals 1 and 2 when testing to prevent backread signals - what exactly does this mean? Have i do remove the 2 termianl when testing the 1 terminal?? Just want to clarify this really and be 100% sure the thermostat has failed before replacing and going off to the diy store.

Thanks in advance.
 
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1-C should be close circuit when calling, you pull the wires out so you don't get a false reading.

For a C plan which as you say is not allowed on new installs.

The grey in the MV is permanent live from the programmer.

C in the cyl stat goes to the brown.

White is the room stat on and pump.

Orange is the boiler.

T1 in the cyl stat is the call from the programmer.
 
Thanks for your help. I understand the wires and how they shouls read (now)! .. but when you say pull the wires out for testing (obviously with the power off and 3 amp fuse removed) - but do you mean take a reading of the wires with the wire ends loose and removed from the wiring centre terminals ? or do you mean remove the other wires in the same terminal blocks that i am testing? thanks for helping.
 
Obviously you make it safe :eek:

You are testing the cylinder stat not the wires.

With the wires removed from the stat C-1 should be closed circuit when calling, if it aint it's busted.

If it is then the problem is elsewhere, most likely the Mv.
 
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OK so i leave the wire in the stat from the programmer (hw on terminal) and remove the other 1 (the C terminal in my case).. and c and 1 should be live (240V betwene them, otherwise the stat is not making) - i have never known to test this way before - always tested the wiring centre terminal boxes.
 
ok good idea - will try this; all fault finding guides mention testing via the wiring centre terminals though - and i was curious about what to remove exactly to prevent the chance of backread signlas from other controls, etc.

i will try your way now tho... thanks for your advice.
 

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