Learning Thermostat advice

milgo

LateStarter said:

Thanks, I've been reading up on the Drayton, and it seems they've got a separate unit (costing hundreds of pounds) for UFH. It seems very much overkill, and I can't see if the standard thermostat will do underfloor.

Bumping in the hope someone with experience sees this.

Is your UFH just 1 zone or many?

How many loops connected the UFH manifold & do they actuators on them?

I'm currently using a Drayton Wiser 3 channel controller (Hub-R).  Currently only 2 zones are connected/in use, DHW, & CH (radiators).  I'm in the process of having wet UFH installed in a new kitchen extension.  This UFH will be connected to the 3rd channel on the controller.

In my case, I will not need the Drayton UFH controller (to control actuators for separate heating zones) as I will only have 1 zone (3 loops) on the UFH.  

Marypw

We have underfloor electric heating in our orangery as advised by the architect. I
It can be timed and set at any temperature you want, but it is phenomenally expensive and we wish we'd just extended the central heating.
We've now got Hive and we put the thermostat in the dining room between the orangery (cold) and the kitchen (too hot) and this works brilliantly - its easy to boost the central heating if necessary for an hour or so. We also have a small electric radiator for instant heat.

LateStarter

milgo said:

LateStarter said:

Thanks, I've been reading up on the Drayton, and it seems they've got a separate unit (costing hundreds of pounds) for UFH. It seems very much overkill, and I can't see if the standard thermostat will do underfloor.

Bumping in the hope someone with experience sees this.

Is your UFH just 1 zone or many?

How many loops connected the UFH manifold & do they actuators on them?

The underfloor (AFAIK is only 1 zone). I can only see one set of hoses on the manifild pump, and 1 actuator and it's all controlled by 1 manual thermostat.

LateStarter

ChaunceyGardiner said:

I'm a satisfied Tado customer, although I have no experience of UFH. Perhaps this is of use: How does tado° control underfloor heating systems? | Help Center

Thanks - it sort of suggests that it's just a learning thermostat controlling a single zone, and any other systems should work the same.

fergie_

Honeywell Evohome is absolutely brilliant (but not the cheapest) and will do everything you ask. It is also one of the few that has an internet gateway, but doesn't use wifi to speak to the boiler or valve units.

Matt_OX4

We have a very similar system to yours with wet UFH only in the kitchen which was extended by the previous owner with a Hive thermostat on the wall - it isn't "smart" as Hive needs the hub which is registered to an individual rather than the house as far as I understand it, and I could never be bothered to get another one just to be able to change the temperature in my phone. It is very very slow to change temperature but then stays lovely and warm.

It's taken me a while to work out how the system actually works, but I think it uses the water that's in the heating system and only calls for more heat when the water gets below a certain temperature, as the boiler isn't always on when the pump that moves water around the UFH loop is going, but I've got my hearing engineer coming in next week and am going to confirm with them. Due to the slow reaction speed what I've started doing is in winter just leave the thermostat at 19.5c (might be 19c this year!) rather than try and time it, which worked well.There were a couple of days when the floor was cold (which you really notice because you get used to it being toasty!) when the temperature must not have dropped overnight, so maybe I do need one early time zone to force the system to call for heat at say 3am so it's warm underfoot first thing.

Workerdrone

fergie_ said:

Honeywell Evohome is absolutely brilliant (but not the cheapest) and will do everything you ask. It is also one of the few that has an internet gateway, but doesn't use wifi to speak to the boiler or valve units.

Second that for Honeywell Evohome. Ive no experience of Drayton but Evohome has nice optimum start and optimum stop times which continuously If you want a room warm by 7am, evohome learns (in practice the algorithm adjusts) when to start and stop the heat demand to that zone.

The only time optimum start doesn't quite get it right is if you have a sequence of warm days followed by a sudden cold snap. The learning is based on a PID algorithm so there is a degree of hysteresis inbuilt. It will sort itself out but can take a day or so to do so. In practice though temperatures tend to cool progressively as we heat into winter.

It's pretty bulletproof as a system though expensive. it also supports opentherm if you opt for the opentherm boiler control module so it can modulate your boilers flame down when there is low heat demand rather than cycling as many other systems do.

[Deleted User]

Workerdrone said:

fergie_ said:

Honeywell Evohome is absolutely brilliant (but not the cheapest) and will do everything you ask. It is also one of the few that has an internet gateway, but doesn't use wifi to speak to the boiler or valve units.

Second that for Honeywell Evohome. 

Sorry, not worth the investment in my opinion. I base my comment on 5 years of use in a previous home.

If a home is well-insulated and use is made of existing thermostats and TRVs, then any Evohome savings are small. Components such as the HW kit (CS92) are anything but robust - replaced twice in 5 years. Similarly, we had one BDR and one controller failure. There is also the cost of replacement batteries to take into account. We also returned home on two occasions to a frozen controller screen  (blue screen of death).

The purchaser of my previous home was so enthused about Evohome that he agreed to my asking price without demur. A year later, I got an email from him to say that he had reverted back to standard heating controls.

matelodave

Bear in mind that underfloor heating in a slab works just like a storage heater and so can take several hours before it even gets warm and then several hours after it's been turned off to cool down again so it's not ideally suited to being turned on for a couple of hours and then off for 8-10 and then back on again for another couple of hours.

TBH having a smart thermostat is a waste of time with an underfloor system which has a high thermal mass because it takes far too long for the system to respond to the thermostat especially if you only want short heating periods.

Ideally it needs to be on to provide background heat for most of the time rather than on/off like a radiator system. Thats why they are suited to heatpump system where the heatpump runs at a low temperature for most of the day, with a night setback of a couple of degrees.

Our underfloor heating can take up to 24 hours to get the room up to temperature from stone cold as it's part of a heatpump set up which runs at a low flow temp of around 35 degrees almost continuously in the winter. Even if I wind up the flow temp it still takes ages to reheat. It suits us though because we are at home all day nearly every day.

Our system has multiple zones, but as the response times are so slow, we only set them back by a couple of degrees overnight

smjxm09

Underfloor heating should be run for long periods but at low temperature and not treated like a radiator.