HCC80 and boiler modulation
Posted: Fri Dec 13, 2024 1:34 pm
I wonder if I'm the only person seeing this potential issue...
I'm a long term and very happy Evohome user with mostly HR80 and HR92 radiator controls but with a couple of underfloor zones controlled by a first-gen HCC80. This has been working fine for several years.
A few months back I replaced my old oil boiler with a modulating (oil) Sapphire with the Opentherm interface. I initially added only the radiators and was very glad to see the Opentherm bridge (in the Evohome Summary Settings screen) frequently showing the boiler modulating down to lower percentages - something I'd not seen before with my old on/off boiler triggered from a BDR91.
I then added back in the HCC80 but quickly noticed modulation seems to have gone. Underfloor works fine but I only now see 100% on the display - never a lower rate and the boiler seems to cycle frequently as a result. Thinking I must have done something wrong, I removed, again factory reset and re-bound the HCC80 - but this has made no difference.
Is this normal? I'd have thought if anything called for 'long and low' heat this would be underfloor heating?
If I knew this was a failing with the HCC80 that was resolved in the newer HCC100, I'd buy that, but it seems a pricey leap of faith!
Thanks for any help you can give me.
I'm a long term and very happy Evohome user with mostly HR80 and HR92 radiator controls but with a couple of underfloor zones controlled by a first-gen HCC80. This has been working fine for several years.
A few months back I replaced my old oil boiler with a modulating (oil) Sapphire with the Opentherm interface. I initially added only the radiators and was very glad to see the Opentherm bridge (in the Evohome Summary Settings screen) frequently showing the boiler modulating down to lower percentages - something I'd not seen before with my old on/off boiler triggered from a BDR91.
I then added back in the HCC80 but quickly noticed modulation seems to have gone. Underfloor works fine but I only now see 100% on the display - never a lower rate and the boiler seems to cycle frequently as a result. Thinking I must have done something wrong, I removed, again factory reset and re-bound the HCC80 - but this has made no difference.
Is this normal? I'd have thought if anything called for 'long and low' heat this would be underfloor heating?
If I knew this was a failing with the HCC80 that was resolved in the newer HCC100, I'd buy that, but it seems a pricey leap of faith!
Thanks for any help you can give me.