Hive/nest thermostat

[AdamD]

I’ll be honest I don’t really know how it works but looking for advice. Have a combo boiler, standard installation. Am interested in being able to use hive or nest to be able to isolate which rooms are heated, ie. heat one in particular at a certain point of the day. - I doubt it’s even possible but a friend mentioned hive and nest and suggested it is, but I can’t see how without getting the entire system changed to a smart system.

Any advice appreciated 

[DamonHD]

There are solutions such as ... ahem ... Radbot, which don't need any particular central hub/stat and help manage the temperatures in each room automagically.

[AdamD]

17 minutes ago, DamonHD said:

There are solutions such as ... ahem ... Radbot, which don't need any particular central hub/stat and help manage the temperatures in each room automagically.

Interesting but it seems like it optimises for occupancy etc, but how does that work with a bedroom for example when you’re only there at night but could be the biggest and room in most need of heat?!

[JohnMo]

You can easily heat individual room with enough zone valves or radiator valves. But you get to the point that boiler cannot turn down output far enough and you get short cycling - basically burning loads of gas for little gain.

 

21 minutes ago, AdamD said:

smart system.

That just means remote access, so nothing smart just an on off device with internet access.

[AdamD]

36 minutes ago, JohnMo said:

You can easily heat individual room with enough zone valves or radiator valves. But you get to the point that boiler cannot turn down output far enough and you get short cycling - basically burning loads of gas for little gain.

 

That just means remote access, so nothing smart just an on off device with internet access.

Got 10 rads in the house, just looking for a way of doing it without spending my life going round the house turning a load off to just heat one room and then turning all back on again to heat the others. Basically we epically failed when doing a loft conversion by only having one rad in the new room upstairs so just looking for the best methods to heat it better without ripping the arse out of it to put another rad in!

[JohnMo]

Your best way to heat almost any house is low and slow, just keep the house heating ticking over. Heat one room, you are really trying to heat the whole house via one room. The external house walls leak heat more slowly than internal walls and doors.  So you have one radiator on it runs balls out trying to make up for the heat slipping through the internal walls to adjacent rooms. 

 

By low and slow is more about room temps. The normal way is via short time slots, every time to switch heating on, you have to heat the building fabric, all the metal in the heating system etc, so you over compensate with higher room temps. As cold walls suck the heat from you, heavy radiator driven air currents drag cold air about etc. Leaving heating on for long periods with small nightly setbacks, allows the whole house temperature to stabilise, boiler moves to a more tick over mode than flat out for short periods.

 

My sister did exactly the same as you are trying, I convinced to try longer run times with no zoning, the house became more comfortable, rooms that didn't heat well, all became comfortable, heating cost hardly changed.

[marshian]

58 minutes ago, AdamD said:

Got 10 rads in the house, just looking for a way of doing it without spending my life going round the house turning a load off to just heat one room and then turning all back on again to heat the others. Basically we epically failed when doing a loft conversion by only having one rad in the new room upstairs so just looking for the best methods to heat it better without ripping the arse out of it to put another rad in!

 

Micro managing room temps with "Smart" TRV's done that - it's great fun developing really accurate schedules for every room 

 

Trouble is it kills boiler efficiency - stone dead

 

Heat all rooms to a lower temp using lower flow temps - no TRV interventions - your boiler will thank you because it'll always have a decent circuit to work with

 

Your wallet will like it because short cycling gas boilers will burn thro gas whilst providing little in the way of heat to the home.

 

  

[torre]

I've only used tado but think they all work the same way. The main thermostat replaces your existing and it's this that calls for heat from the boiler on a configured schedule and temperature.

 

Then an extra TRV or sensor can be installed in any room that you want to be able to control separately - kept warm or cold according to it's own temperature schedule.

 

The TRV signals the main thermostat to call for heat, heat still pumps around the whole system though, through any radiator with an open TRV whether that's a smart or a dumb one.

 

As others have said, at the extremes this can be quite inefficient, but if you've a couple of rooms and know one will be empty while the other is used, you can avoid heating the other, while the rest of the house is somewhere between. Say you want your office warm in the day and your lounge warm in the evening.

[torre]

1 hour ago, AdamD said:

only having one rad in the new room upstairs so just looking for the best methods to heat it better

So you basically want something thing that signals "I'm still cold up here, keep the boiler on!"?

 

A smart thermostat with a smart TRV on that radiator should do that. Not sure it's much cheaper to install or run than a bigger radiator though

[-rick-]

1 hour ago, AdamD said:

Got 10 rads in the house, just looking for a way of doing it without spending my life going round the house turning a load off to just heat one room and then turning all back on again to heat the others. Basically we epically failed when doing a loft conversion by only having one rad in the new room upstairs so just looking for the best methods to heat it better without ripping the arse out of it to put another rad in!

 

Reading between the lines it sounds like you don't feel you get enough heat in the loft conversion so to get that room hot you have to turn off the other rads (either because it doesn't get hot otherwise, or by the time it does get hot the rest of the house is boiling). That sounds like something is wrong with your system.

 

If starting from a cold house, turn up all the radiators and turn on the heating. All the radiators should get hot at roughly the same speed. If that doesn't happen then your system isn't balanced and some of the hot water might be short circuiting back to the boiler before it reaches your cold room. If this is the problem then the first step is balancing the radiators and then coming back with more info on your system if this doesn't solve things.

 

I've just been doing similar in my place. Once you have things roughly balanced you should be able to just use normal TRVs to adjust individual rooms. Yes this still means all the rooms heat at the same time, but rooms should warm in approx the same time. If, like me, some of your rooms have woefully undersized radiators then you still might have a problem, but smart heating won't solve that.

Edited 9 hours ago by -rick-