Pump remains intermitantly on

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Hello all. I've installed a new tado system (TRVs in every room, self-installed wiring on a GlowWorm Ultracom2 cxi combi boiler).

While the radiators are warming up (and cooling down) according to the schedule; I can hear the pump on the boiler working away - water moving through the system) even when the radiators aren't calling for heat.

It doesn't do this all the time, it does it intermittently for ten minutes or so, stops, then another ten minutes and so on. The radiators don't warm up. It's going intermittently all through the night and the low humming noise of the pump working away is annoying. It didn't do this pre-tado.

Any ideas gratefully received. 🙂

Answers

  • wateroakley
    wateroakley ✭✭✭
    edited August 2023
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    This sounds like pump a over-run issue. Some newer system boilers will have an internal bypass. Some boilers will require an external automatic or manual bypass.

  • Sounds like an interesting thing to look into - thank you!

  • KitKat
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    Hi, did you get anywhere with this?

    We have a very similar problem with the same setup (Glowworm Ultracom2 CXI, 3 TRV's, 2 wireless temp sensors)

    The heating pump comes on in the night even when Tado is not calling for heat. The boiler timer is set to 'on' 24/7, so I'm wondering what else could trigger the pump to fire besides Tado calling for heat?


    Thanks.

  • We have the old timer set to always off and, illogically, it seems to work fine. Anyway, it seemed to resolve itself after a while - the pump turns off about ten minutes or so after the radiators stop calling for heat.

    Another thing to try might be the "Early start" setting on each radiator. Our bathroom is quite chilly and we wanted it to be 21C by 7am, so with the "early start" setting the radiator was coming on at 3am in the winter as it needed 4 hours to get the room up to temperature. So we just turned that setting off.