Posted by: @gutoffowc

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Does anyone know if a wired system to the existing thermostats can be adopted? Rather than the wireless Sensocomfort system proposed?

 

It can be done but really, really, don't, you will regret it and you will suffer exactly the problems your installer is predicting and almost certainly incur higher heating bills and lower comfort than you need to.

Modern heat pumps with inverters and good weather compensation should almost always be controlled solely on their native controls and, in a moderate size house (say 200sq m or less), generally with only one zone, balanced to give just the correct amount of heat when operated 24x7. 

Use the sensocomforts (or just one sensocomfort), the key functions are actually really simple once to operate you get your head around them and, properly adjusted, you will hardly ever need to touch them anyway.  If you really want you can use a sensocomfort just like a thermostat (but one that actually works with rather than against the heat pump) by setting heating mode to 'active' (your installer will recognise this).  This is what I do in late spring when solar gain tends to dominate, the rest of the time its on pure WC. 

I change the settings on mine perhaps twice per year, the rest of the time it just does its thig keeping the house comfortable 24x7, something I never achieved with my old gas boiler.  Except at the very end of the season the control doesn't take any notice of indoor temperature, it runs purely on weather compensation which works a treat. 

If you wish to post a floorplan, and indication of what controls what Im happy to make suggestions.  Now is a good time IMHO to get the maximum benefits of the modern heat pump plus UFH combination you have even if it takes a bit of re-learning.

Is your house really 10kW?

Posted by: @jamespa

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Posted by: @gutoffowc

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Does anyone know if a wired system to the existing thermostats can be adopted? Rather than the wireless Sensocomfort system proposed?

 

It can be done but really, really, don't, you will regret it and you will suffer exactly the problems your installer is predicting and almost certainly incur higher heating bills and lower comfort than you need to.

Modern heat pumps with inverters and good weather compensation should almost always be controlled solely on their native controls and, in a moderate size house (say 200sq m or less), generally with only one zone, balanced to give just the correct amount of heat when operated 24x7. 

Use the sensocomforts (or just one sensocomfort), the key functions are actually really simple once to operate you get your head around them and, properly adjusted, you will hardly ever need to touch them anyway.  If you really want you can use a sensocomfort just like a thermostat (but one that actually works with rather than against the heat pump) by setting heating mode to 'active' (your installer will recognise this).  This is what I do in late spring when solar gain tends to dominate, the rest of the time its on pure WC. 

I change the settings on mine perhaps twice per year, the rest of the time it just does its thig keeping the house comfortable 24x7, something I never achieved with my old gas boiler.  Except at the very end of the season the control doesn't take any notice of indoor temperature, it runs purely on weather compensation which works a treat. 

 

If you wish to post a floorplan, and indication of what controls what Im happy to make suggestions.  Now is a good time IMHO to get the maximum benefits of the modern heat pump plus UFH combination you have even if it takes a bit of re-learning.

Floor plan of ground floor enclosed; Apologies for the poor quality. Its the UF layout.

What I believe is the issue; the hall is a two storey height presumably served by the same proportion of UF heating is always going to take longer to heat up.

The main living area heats up nicely, and the thermal mass of the floor gives it a nice constant temperature.

The small room in the corner is always slower to warm up, maybe the ratio of wall area to floor area means a higher heat loss on the north side of the house?

Do you have rads or underfloor heating?

My original question remains the same. If it's measuring the temperature in one room only then will it give inconsistent heating on the ground floor??

Posted by: @gutoffowc

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Floor plan of ground floor enclosed; Apologies for the poor quality. Its the UF layout.

Do you have rads or underfloor heating?

Nothing attached!

I have rads but UFH makes the case for not using thermostatic control (and certainly not third party thermostatic control) even stronger, because of the long reaction time due to the thermal mass.

Posted by: @gutoffowc

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What I believe is the issue; the hall is a two storey height presumably served by the same proportion of UF heating is always going to take longer to heat up.

Is there no heating at the top?  If not then yes this may be a degree cooler unless you balance the loops.  That said does it matter in a hallway?  

Posted by: @gutoffowc

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My original question remains the same. If it's measuring the temperature in one room only then will it give inconsistent heating on the ground floor??

Not if its properly balanced.  The manifold should have adjustment (flow regulating) valves which enable you to tweak the flow through the various loops, which tweaks the relative amount of energy that goes in thus compensating for the different loss to UFH area ratio.  They should be adjusted (balanced) to get even heat when the heat pump is operated 24x7 with any zone valves/thermostatic control of individual loops or groups of loops disabled (which you can do by turning the target temperature on any thermostats controlling the zone valves up to max).

There is an article here on radiator balancing, UFH loop balancing is the same principle (for LSV read flow regulating valve - on the manifold), although less critical because the fact that UFH operates at such a low temperature means that it is almost self-adjusting.  With an open plan layout even less critical still!

It might be worth your while reading this introductory article.  Heat pumps (and the understanding of how to get the best out of them) have moved on a lot in the past 5-10 years).