Hive System

[iabm12]

Hi all,

I hope this is okay to post here, apologies if there is a separate area for Hive.

A little bit of a back story. I moved into my current house a few months ago, it was built in in 1984 and is EPC rated C (not bad when the other houses we looked at that were smaller and the same age where EPC D and lower). The boiler had been moved into the loft and the old thermostat looks to have been from c. 2005, a Danfoss TP5 (I think). For whatever reason it wouldn't programme and so we were having to manually turn it on and off.

We got the Hive mini so we could set when the hearting comes on and set it to come on when it falls below a target temp.

I have a few questions but the main one at the moment is:

1) how long does it take or should it take to get to target temp? For example, we set it on the schedule to get to 23.5 in the morning between 06:00 and 08:30. When I got up this morning before the schedule started the house temp, according to the app was 17.1. The hearting did come on at 06:00 but even after two hours, it says the actual temp is 18.6 and it is heating to 23.5. My question is, does it take time to get to the target temperature and what if, at the end of that schedule it isn't at target temp?

Apologies if this is really simple and either I've got the wrong end of the stick or I'm being thick.

Any advice and tips welcome!

Thanks,
B.

 

[Mottie]

23.5° from cold will take some time. Once there, maintaining that temp is easier - just like the speed of a car! We have ours set at 21° from 5.30 and it’s there or therabouts by 6.30ish. Our 18Kw boiler is set at 15Kw max output.

What settings do you have your boiler max temp output on?

 

[stem]

That will depend upon the heating system it is controlling and whether or not it can produce enough heat. When it's as cold as it is presently I doubt my central heating would get to 23.5 degrees if it was running flat out all day. Which is pretty hot, the recommended setting is usually somewhere between 18 to 21 degrees C.

So my question is are the radiators hot? particularly the one in the room where the Hive thermostat is located. If so, there's probably nothing you more you can do. All a thermostat will do is switch the heating off when the set temperature is reached. It can't make it produce more heat than it is physically capable of doing.

 

[iabm12]

@stem thank you for the reply. The radiators are hot, yes. The thermostat was in the kitchen overnight and it is cooler in there anyway due to the size of it. I suspect it is probably better have the thermoset on it's stand in the warmer rooms. We're also in the process of swapping the rads for newer double ones which I'm sure will also make the difference.

It's a new thing for me to get used to and so I'll probably be playing about with it and faffing with the schedule and temps.

 

[iabm12]

@Mottie - thanks for the reply. I'm not sure on the boiler settings, I've not looked. I can later though. We had the plumber in there a week back after he'd put a new rad in so I'll see if he remembers (he usually does).

I just wasn't sure if it sated on to get to that temp or not.

Another question, if I have schedules set but pop it into manual mode, setting the target to 18, I assume if it falls below 18 it would come on and the schedule would still work?

B.

 

[stem]

The thermostat was in the kitchen overnight and it is cooler in there anyway due to the size of it. I suspect it is probably better have the thermoset on it's stand in the warmer rooms. We're also in the process of swapping the rads for newer double ones which I'm sure will also make the difference.

If you are moving it around, one point to note is that the radiator in the room where the Hive is located, shouldn't be fitted with a Thermostatic Radiator Valve. TRV's can interfere with the operation of Hive and stop it working correctly by turning the radiator down before the set temperature on the Hive is reached, meaning it would never get there.

Ideally the thermostat should be in a cooler room so that the other rooms are warmed up first before the Hive switches the heating off.

Not sure about the kitchen as a location though. When you're cooking and the kitchen warms up the radiators in the other rooms will go off too.

 

[CountryFan]

What type of heating system do you have? As above it could be the boiler settings, however if the radiators are getting hot, it could just take time to heat the property.

 

[Mister Banks]

Today’s smart thermostats need a different way of thinking. In effect the heating is never off, you have a setback temp and a schedule for when you want the house warmer. For example if you normally want the temp to be 21c then the setback temp should be around 18c to enable the heating to reach the scheduled warm up temp of 21c in a reasonable time.

Warmup effectiveness is dependant on boiler flow temp, house insulation, and length of time the boiler is scheduled at the higher temp.

 

[ericmark]

It will depend in so many factors, hot air systems are likely the fastest, had it in first house, but also cooled fast, fan assisted radiators next best, had one in last house, in the living room, together with a 4.5 kW gas fire, and a double standard radiator, and house from cold, approx 10ºC as living with my mother to look after her most of the time, and living room to 20ºC in less than ½ hour, rest of house took longer, but the fan assisted radiator moves the air around.

This house looking at hours, maybe 2 to 3 hours maybe more to go from 10ºC to 20ºC in the living room, also takes a lot longer to cool, so the thermostats set to 17ºC eco setting and 20ºC comfort setting, and at that around an hour to raise the 3ºC.

The heart of the system is the TRV, it is what decides what is heated to what temperature and when, so the likes of the Wiser TRV head will work out how long it takes to reheat, and call for heat so that at the time set it is at the heat set, the TRV wirelessly connects to hub, and hub tells the boiler when to fire, and if an OpenTherm boiler, then how much heat is required, the EvoHome does the same, there is no need for a wall thermostat, but Evohome does have a control panel and Wiser can also have wall thermostats if you want, not sure about Tado, how that works, Nest does not connect to TRV heads so a bit useless, Hive does not have OpenTherm but many boilers are not OpenTherm enabled any way.

I tried geofencing with Nest, it was useless, can't set distance only the Eco and Comfort setting, so abandoned that idea. But setting the TRV heads in sequence works, only needs 10 minutes between main rooms, so kitchen, dinning room, then living room, means rooms heat in that order.

Hive is an odd thermostat for some reason once the wall thermostat hits 22ºC it will not accept any calls for heat from other rooms. I have Nest which proved a bit useless, and Wiser which has not been in use long enough to really know how it works, but so far it seems OK and to date 9 programmable TRV heads non linked to hubs.

 

[Mottie]

Another question, if I have schedules set but pop it into manual mode, setting the target to 18, I assume if it falls below 18 it would come on and the schedule would still work?

Yes. If you pop it into manual mode and set to 18°, it would come on at anything below that. However, in manual mode, the schedule would not work as you will have taken it out of that mode.

For what you want, set your schedules and your temperatures and set the 'at rest' setting to 18°, then even when off, it will come on if the temperature drops below 18°.

 

[iabm12]

Thanks, @Mottie - daft question, is the 'at rest' setting just the blue one out of two? Currently it is set to 7 degrees.

I know it is probably person to most and largely depends on house size etc. but if anyone has a schedule they use that works and wouldn't mind sharing it as I learn the ins and outs of Hive, that would be great!

 

[Mottie]

Thanks, @Mottie - daft question, is the 'at rest' setting just the blue one out of two? Currently it is set to 7 degrees

Yep, that’s the one. Everyone’s schedule will be different. We have one schedule for Monday-Weds, one for Thursday & Friday and another for the weekend. We leave our hot water on permanently.