Heating rewire

Discussion in 'Plumbers' Talk' started by John Berman, Aug 19, 2014.

  1. John Berman

    John Berman New Member

    So hope you can help I have a


    Glow worm Micron FF50 Boiler, Gravity Fed system for Heating and Hot Water

    Hot water - works and boiler kicks in when required, the temperature is not controllable, probably due to the fact that there is no cylinder stat.

    Central heating - Works in that it will heat up - there is no Room Stat just a cable out of the wall, so to get the heating on I manually move the lever on the valve

    So the physical plumbing is good and works, the wiring is a mess see picture

    The valve is a Honeywell 3 way with 5 Wires
    Oh and there is the Programmable timer for Hot Water and Central Heating

    So my plan is to


    Buy a Cylinder Stat - Honeywell L641A Cylinder Stat - http://www.screwfix.com/p/honeywell-l641a-cylinder-stat/40051

    Buy a Room Stat - Honeywell T6360B Room Thermostat - http://www.screwfix.com/p/honeywell-t6360b-room-thermostat/26159

    Buy a HVAC Wiring Centre, Honeywell 42005748-001 - http://uk.rs-online.com/web/p/hvac-wiring-centres/2001342/


    Looking at the wiring centre it seems to clearly show which wires go were

    Am I on the right lines ?

    Regards

    John Berman mess.jpg
     
  2. itchyspanner

    itchyspanner Member

    check your boilers instructions before you do anything, check if theres a need for a pump over run, check you have the right amount of cores at each point. then gew for it if your competent with electrics, safe isolation etc.....
     
  3. John Berman

    John Berman New Member

    Thanks, well I have checked the manual and no mention of Pump Over Run, what do you mean by Cores at each point ?

    Thanks in advance
    John B
     
  4. Rulland

    Rulland Screwfix Select

    The amount of wires required at each point ie if your stat requires a live, switched live and a neutral (+earth) its no good if you only got a two core cable going to that position.
     
  5. John Berman

    John Berman New Member

    understood, so quick check shows that thermostat has 3 cores so thats a plus although I guess 4 core would be better - i can install new cable prior to carpets going down
     
  6. itchyspanner

    itchyspanner Member

    plan it out, plan the position of everthing, run cables with the correct number of cores, wire up when ready/ as a final fix.

    note you can not use the uninsulated earth in twin/ three and eath cable as a live cable, if unsure run an extra cable. make sure there is an earth core at each point even if its not needed, it may be needed at a later date.
     
  7. John Berman

    John Berman New Member

    so bits have arrived but im confused (already) the Wall Stat has 4 connections and an Earth so I laid a 5 core back to the wiring centre, that however only has 3 connections for the room stat ?

    I also note that there is a HTG Valve and a MID POSN or HW Valve - No I have a 3 way port valve so which is this in the wiring centre.

    Thanks in advance
    John B
     
  8. sam spade

    sam spade Active Member

    [QUOTE="John Berman, post: 1307146, member: 117144]the Wall Stat has 4 connections and an Earth so I laid a 5 core back to the wiring centre, that however only has 3 connections for the room stat ?[/quote]
    You will only use three connections on the stat - 1, 2 and 3. Pity you purchased an almost obsolete stat (about 30 years old). A modern digital stat is so much better, eg Honeywell DT 90E

    The 3 way valve is normally called a mid-position valve.
     
  9. John Berman

    John Berman New Member

    thanks for that, so out of curiosity what's the HTG Valve connector block - I assume its to cover all scenarios ?
     
  10. John Berman

    John Berman New Member

    Further to this im going to buy a new programme timer for the hot water \ central heating

    given i have

    Glow worm Micron FF50 Boiler, Gravity Fed system for Heating and Hot Water
    and have bought
    Cylinder Stat - Honeywell L641A Cylinder Stat - http://www.screwfix.com/p/honeywell-l641a-cylinder-stat/40051

    Room Stat - Honeywell T6360B Room Thermostat - http://www.screwfix.com/p/honeywell-t6360b-room-thermostat/26159

    HVAC Wiring Centre, Honeywell 42005748-001 - http://uk.rs-online.com/web/p/hvac-wiring-centres/2001342/

    can anyone recommend a compatible programmable timer

    Regards
    John Berman
     
  11. sam spade

    sam spade Active Member

    It's not clear from your earlier description if you already have a timer. If you do, I suggest you retain it for timing the hot water and buy a programmable thermostat for the central heating. The Honeywell CM9XX is highly recommended. It comes in 24hr and 7 day versions in wired and wireless.

    Send the T6360B back!!

    The "heating valve" connector block is used, in conjuction with the HW block, when you have a system with separate valves to control heating and hot water.
     

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