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Main Eco Compact Combi Boiler

Discussion in 'Plumbing and Central Heating' started by john2k, 1 Mar 2021.

  1. john2k

    john2k

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    A family member just moved into a property that has a new Main brand Eco Compact Combi Boiler which I think is by Baxi, link below seems like this is the one:

    https://www.mainheating.co.uk/main-products/gas-boilers/combi-boilers/main-eco-compact-combi

    There seems to be no room thermostats anywhere in the house at all to control the boiler and as a result the boiler seems to just stay on all the time. There is only two dials that you use to control the heating temperature and the horn water temperature. There is no place to actually turn the heating on or off. I don't see any timer either, otherwise that could have been an option.

    Can anyone advise is there a easy way to turn the heating on and off at the boiler without turning the power to the boiler off and losing hot water?

    Also, how hard will it be to wire some sort of wireless thermostat to this boiler?

    Thank you.
     
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  3. ianmcd

    ianmcd

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    you will have to wire in some kind of external control as long as it is voltage free switching, can be wireless if you want, nothing difficult in doing it , if you can follow basic instructions
     
    Last edited: 1 Mar 2021
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  4. john2k

    john2k

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    Will you be able to guide me which page on the user manual refers to installation of the thermostat? From what I understand a thermostat essentially sends a relay activated switched live to the boiler telling it to turn in right? Could you guide me to the wiring diagram on the boiler end if possible please?
     
  5. john2k

    john2k

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    So looking at the following installation guide: https://mediacdn.mainheating.co.uk/...main-eco-compact-combi-installation-guide.pdf

    Page 42, figure 35 seems to show the connections. I've found a wireless thermostat with opentherm connectors. So I'm assuming I just need to take the live and neutral connections from the boiler to the receiver. And take two opentherm wires to pins 1&2 from the receiver. Any thoughts?
     
  6. sxturbo

    sxturbo

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    be careful, the Baxi doesnt accept "all" opentherm controllers.

    it doesnt work with Hive, i cant remember the issue, but it would turn it on once then continue not to work until it was rest or something, i cant remember exactly now it was a year ago, my boiler install was delayed a few days as the installer was stuck trying to fix it between baxi and nest in the end he had to set it the old fashioned way as it turned out the baxi expects another packet of information which the nest doesn't send or something.

    it should work witht he honeywell t6r though as that sends out virtually all possible opentherm commands/packets, but maybe someone who installs these all the time can confirm.
     
  7. Mr Sparkle

    Mr Sparkle

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    Decent boiler (for the price), crap design

    Who designs a boiler where one is unable to turn off the rads?

    I stuck a google nest on mine.

    Installing a thermostat is easy work. Don't be intimidated and just follow the instructions in the manual
     
  8. ianmcd

    ianmcd

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    yes if using OT if not use diagram G and connect the two blacks to the switching wires on the receiver (will be 240V switching) if you use OT then the yellow wire in diagram G has to be removed, as said Nest supports OT but whether it works withBaxi I cant say but someone else saying it does
     
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  9. Londoner2

    Londoner2

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    I have one of these, as someone said above poor design as you need to have ability to switch heating off on boiler, but no the manufactiruer leaves all that to controls wired in, another thing that would have helped is when in operation it would be nice to have a LED backlight come on the visual screen.

    Mine is controlled by a salus i500 which actually works despite being a bit laggy.

    OT controls lets you control thermostats temp AND water/boiler temp as well (making the dials on the boiler redundant).
     
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  11. john2k

    john2k

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    I've ordered a EPH Combi Pack 4 Wireless Thermostat which I've been told is compatible with this boiler and it's opentherm too.

    Question regarding opentherm, is there a +/- wire or can the wires from the thermostat receiver's opentherm pins go in any direction to pins 1&2 of the boiler terminals?
     
  12. john2k

    john2k

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    Looking at the receiver specs of the EPH Combi Pack 4 wireless thermostat, the receiver spec says it's 10(3)A rated. Is that 3A or 10A? what kind of cable should I use to wire it 1mm2 or 1.5mm2?
     
  13. Alec_t

    Alec_t

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    AFAIK it's 3A for an inductive load, 10A for a resistive one.
     
  14. ianmcd

    ianmcd

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    0.75mm oe 1.0 mm are fine
     
  15. vulcancontinental

    vulcancontinental

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    Plus the EPH is ON/OFF and OT so if one doesn't work the other will. FWIW I believe it will.
     
  16. john2k

    john2k

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    For the OT connection can I use any cable or does it have to be a certain type of cable? What kind of voltage etc will the OT pins carry?
     
  17. vulcancontinental

    vulcancontinental

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    0.5mm it's very low voltage and current. Don't run alongside power or lighting. Usually very short between receiver (if RF stat) and boiler. The electr guy here would probably say network cable, I don't know. I used to run the AQ6000 in bell wire.
     
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