Heat pump- possible to upgrade to smart thermostat?

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rustbucket

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A friend of mine recently renovated an old cottage and had a heat pump installed.

The heat pump came with standard manual digital thermostats (3 wire). Digital display, manual button to adjust temp.

The system is zoned (5 or 6 zones I think)

Is it possible to swap out the thermostats for smart thermostats in a straight thermostat replacement and set up a smart system through the wifi? Or does something have to happen at the heat pump as well? (Some form of extra controller etc)

They want to be able to control remotely

they currently have eph non programmable hdt thermostats

Thanks for any help
 
You can but you shouldnt, heatpump should be set to the temp you want and left at that, not turned on and off like traditional heating.
 
@Blackrock1 thanks for that. I did advise them of same. Unfortunately it probably wasn’t the right system for them to put in as they are not there that often. They currently have it set very low as they are not there.

However a couple of the rooms are a good bit colder than the others (nature of the renovation, old part of cottage vs new extension). They don’t want to have the settings higher in the colder rooms all the time.

I suggested that they might be able to turn those zones up a couple of days before and back again once gone.

I know it’s not ideal but would that be possible? Its no good doing it when there as it takes to long for the few days they use it.
 
Yes that is useful but I dont know the exact details of the system they have. Il get specs and have a look further although as far as I am aware there is no app. just thought I might be able to swap out the therms with smart wifi enabled ones. Thanks for the help
 
I looked at doing something like this previously, but mainly because the stats were poorly located and not particularly accurate

Upgrading Room Thermostats for better control

Some background info: We have a new build (2017) with a Heat Pump and A3 rating, although our usage almost puts us in the A2 (unofficially). We use ~6700/6800 kWh/yr for 130sqm, so we are coming in at approximately ~52 kWh/sqm/yr. I think we could easily reduce that by >300 units with better...
www.askaboutmoney.com

In the end I switched completely to weather compensation so the indoor stats are no longer part of the system. As the outside temperature drops, the HP works a little harder.

Your friend should get rid of the zones, it's counter productive to using a HP. You need to use all available radiator/Under floor surface area to efficiently transfer the heat. Otherwise it will cost them a fortune running in zonal and turning it on/off with an app

Edit:
Even if they don't live there, they should still get rid of zonal and use the weather compensation. They just need to turn the system on ~1 day before arrival so that the temperature stabilizes
 
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It doesn't look like EPH offer a direct swapout for those thermostats to make them 'smart'. Their solution would be to swap to something like these https://www.ephcontrols.co.uk/section/cp4i/ where the thermostat in each room connects back to receivers in the hotpress then a gateway device makes the connection to the Internet. You'd end up with 6 thermostats with batteries in them using radio (not ideal in an old build!) to communicate with 6 receivers and 1 gateway.

A better option for a swapout would be these https://www.heatmiser.com/neostat-wifi/. They use the existing cables in the walls with no receivers or gateways, just directly onto your Wifi. Worth noting they can only switch 3A but assuming these are all wired back to electronic valves that should be no issue.

Depending on how 'hacky' you want to get, another much cheaper option would be put a 'smart switch' on the 'call for heat' wire that is going to the heatpump, which would effectively allow them prevent the heatpump from coming on when they're away from the house and turn it back on remotely a day or two before they arrive. Load of ways to do that, one of these for example https://www.shelly.com/products/shelly-1-gen4. The device connects over Wifi to a cloud service and they provide an app where the user can toggle these switches remotely. Apart from the hackiness of this approach it also does not offer frost protection for the winter months.

The best option though would be an app for the heatpump itself and I'd be amazed if it's not possible, perhaps with the addition of a Wifi module.
 
Thanks for all your suggestions. Il get details of the exact hp system they have and have a look at what might be best/easiestThe current set up is not ideal at all. Il post back with further details once I have them
 
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OKGO said exactly what I was going to say, and use in my own house. Got rid of all the zones on the underfloor/around the house and use weather compensation. I have a Mitsubisi Ecodan and the Melcould app, so can set/reset/schedule at will, including holiday modes.
This will take a bit of investigation and reading/youtubing to get an idea of it. It's not fire and forget like the old systems. A good place to start is the heat geek series which will give you all the info you need, and then some.
 
Buddyboy said:
Got rid of all the zones on the underfloor/around the house and use weather compensation.
Click to expand...
My understanding is that in this case the owner wants to be able to heat all rooms minimally when they're not there, but dial up specific rooms which have a higher heating load when they are in the house. Doing that using my system (and I guess yours) would mean manually messing around with the balancing valves to each circuit each time they arrive/leave. But I agree, they should forego that requirement as I think the saving in just leaving the HP in frost protection heating only while they're away will be much more significant, they just need to figure out how to get it out of that mode a few days before they arrive remotely.

On a related note, when I had my BER assessment done after the HP install I was told that because I didn't have individual zone control I got an A3 instead of A2 rating. The BER assessor agreed with me that zones were not the recommended or efficient way to use a HP but the rating system does not currently factor that in.
 
Zenith63 said:
but dial up specific rooms which have a higher heating load when they are in the house.
Click to expand...
Based on my reading/watching of heat geek etc., I think this is a bad idea and can work out more expensive. For two reasons

1. The greater volume of heat bearing material you use, (i.e. water), and larger surface area of emmitters (i.e. rads in this case), then the more efficient the heat pump will operate, and the lower the necessary temperatures. Keeping a room/house warm with 10 gallons of 25 degree water will be more efficient then trying to heat it with 1 gallon of water, which will need a far greater temperature. For example, underfloor heating is more effieicnt than radiators with heatpumps due to the greater volume of lower temperature water. Heat pumps are more efficent/cost less the lower the temperature they generate. In other words, having all radiators warm is more effient that having a few hot, and the others turned off. I have opened all TRVs on my rads fully for this reason (again as per heat geek).

2. As per heat geek, treat the house as the heating envelope, as the external walls are (hopefully ) insulated. By trying to heat one room, you need greater temperatures. Firstly because of point 1 above, and secondly because heat will travel to the adjacent (colder) rooms, meaning that you have to provide more/hotter heat to the one room. Also, every time you open a door, the heat will transfer between the hot and cold rooms. In my opinion, you are better to keep the whole house at an even temprature.

I know I'm referencing Heat geek a lot, but he is only one of the sources I've looked at, but does contain all the information you need.

And finally, I agree, having the house set as frost protected, then dialling up the heat a few days before they arrive will make most sense.

Re-reading the OP, they don't state if the renovation included underfloor, or improving/increasing the size of rads (emitters), which will have a large bearing on how they operate the heatpump.
 
The house has underfloor heating. No rads.
Externally insulated all round.

Original cottage old stone walls. New extension added block built. Single storey cottage.

The issue is mainly
1. Original cottage seems much colder when there than extension even though all thermostats set to same temp.

The heat pump was recently serviced so no issue with heat pump.

2. They want to be able to control it remotely as they don’t use it very often. Happy to leave it on frost mode or low setting all the time but the two rooms In the old part need more heat so they want to be able to turn those up a few days before they arrive.

I’m not sure if it’s something to do with the old stone walls and air loss between the insulation or something like that in those rooms.

Il post details of the system when I get them.

I thought there might be an easy solution but it seems more complex.

A regular boiler would have been better for their needs I’m guessing
 
rustbucket said:
The issue is mainly
1. Original cottage seems much colder when there than extension even though all thermostats set to same temp
Click to expand...
I would rephrase this as the symptom, not the issue.

The real issue is the HP setup. There should be no reason why it can't heat the place properly.

My guess is that the system is not balanced and the flow temperature (or heat curve) is not set properly.

Your friends should do the following:
- don't make changes until September/October when outdoor temperatures are lower.
- don't make any changes until they plan to be in the house for at least 3/4 days in a row
- Be patient, HP's are low and slow so changes take time to effect the comfort level, i.e. one change per day
- Balance the UFH, the cold rooms need more flow and the warm rooms need less.
- Increase the flow temperature, this should mean more heat in and the stats will control the already comfortable rooms
- They might need a plumber to help them with the last steps if they are not comfortable with it
rustbucket said:
A regular boiler would have been better for their needs I’m guessing
Click to expand...
Longer term, they need to learn how to operate a HP correctly. They are different systems that can both do the same job. I would follow the advice of @Buddyboy above and learn from Heatgeek website and videos

If they solve the short term problem of temperature imbalance, then longer term they can start working towards removing the zones and gradually dropping the flow temperature until the house finds a nice equilibrium
 
Many thanks for all your input guys. I will pass on the heat geek links and suggest they wait until Sept before making any changes
 
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