Upgrade thermostat to improve heating efficiency??

RaulDublin

Need some tips on thermostat replacement and heating system.

We are in an old 70s build 4 bed semi d house with an OFCH where we moved in 2 years back...House is recently refurbished and quite well insulated.
There's an old thermostat and timeclock.
Downstairs -Horstmann H37XL Channelplus Electronic programmer on which we normally use the boost function whenever we want the heating / hot weather to go on . Heating is ON on an average 2/3 hours a day.
Downstairs and upstairs hallway we have a Horstmann HRT3 - Room Thermostat and they don't seem to be working properly . I have the temp on them set to max as when the temperature on them is low as in 21 degrees or so the radiators don't seem to very hot.
Its not big issue as a 1 or 2 hour boost seems to be enough to warm up the rooms for a good while and if needed we top up with a 1 hr boost for the upstairs heating before bed.
We have TRVs on all radiators except the 1st one and would like to upgrade the thermostat/ channel programmer/ timeclock to a system which turns off the heating automatically or dosent turn on A particular rad if the temperature in the room is around 20/21 .
We don't have that working now so we are probably wasting heat in a way albeit the boost being only for a 3/4 hours a day ..?? and are wasting the TRVs as they are open .
I heard about the hive systems which are good looking and app controlled etc but how would it compare to a basic boost function which we have been using ??
Do we consume more oil in heating a house with an always on system where the boiler kicks in when needed to set the temp to desired compared to what we are using right now (boost when we need ).
We've used around 1300 liters of oil since mid feb last year when we ran out of oil and would top up again in Feb which is probably a lot ?
Any tips would be great !

I've attached a pic of the thermostat and the programmer..

youtheman

A thermostat is a simple switch that opens when the temperature is above the set point. So the technology hasn't changed in years (you can get fancy digital ones, you can get combined thermostats and timers etc., but the thermostat is still a simple switch).

You do mention that 2 of the thermostats are in the hallway. In my opinion that in a real 1970's way of thinking - you're not living in the hallway so why are you trying to control the temperature in the hallway.

Looks like you have a modern 3 channel timer. The thermostat beside it looks ok, it's a simple mechanical dial unit.

Do you have radiators in the hallway ?. If you have a thermostat in the hallway then you really need a radiator in the hallway. If I were you I'd try move the two other thermostats into a living room or a bedroom (make sure you remove the TRV in that room, or at least turn it fully up). Then the thermostat should control the temperature at the set point you chose (assuming the radiator is sized correctly). Hopefully the other rooms in the same zone will reach a similar temperature (but you can adjust them somewhat with the TRVs).

Sorry for the long winded reply.

RaulDublin

Thanks for the reply .
There are two thermostats one in the dining next to the controller and another in the the hallway .in total the one upstairs seems to be not working .We do have a small radiator in the hallway .

youtheman

You can easily check if a thermostat is working. Turn the zone 'on' via the controller. Turn the thermostat fully down and check that the zone valve is closed. Then turn it fully up, you should hear it click (i.e. the switch operating) and the zone valve should now be open.

RaulDublin

I tested with the value open and closed . With the heating on the one downstairs does click and a small red led dot comes up when the dial is between 12 and 15 degrees ( max is 35 ) . With the one upstairs I hear a click unless it is at 25 deg, i dont get the led dot as well .

RaulDublin

youtheman wrote: »

You can easily check if a thermostat is working. Turn the zone 'on' via the controller. Turn the thermostat fully down and check that the zone valve is closed. Then turn it fully up, you should hear it click (i.e. the switch operating) and the zone valve should now be open.

Thanks youtheman.
I managed to try the faulty /suspected thermostat with reduced temperature setting of around 19/20 degrees .

I could see the rads in all the bedrooms heat up and are quite hot to touch.I opened the TRVs in all the rooms to around the high mark or around 24 degrees.

Kept the heating on for a 2 hours and could see with with a baby monitor that the rooms heats up to around 20 degrees.Afterban hour of heating the rads go lukewarm and that's probably because the thermostat in the upstairs hallway is at 20 degrees already and turns off the boiler ..?

The Horstmann HRT3 has a small red dot /led which goes off and then never goes red when the temperature dips to lower than 19/20 degrees and sometimes I could see it flicker when I moved the dial.

When I set the temperature to max on the thermostat, the rads heat up again but the light on the thermostat does not go on 😊.

xl500

youtheman wrote: »

A thermostat is a simple switch that opens when the temperature is above the set point. So the technology hasn't changed in years (you can get fancy digital ones, you can get combined thermostats and timers etc., but the thermostat is still a simple switch).

You do mention that 2 of the thermostats are in the hallway. In my opinion that in a real 1970's way of thinking - you're not living in the hallway so why are you trying to control the temperature in the hallway.

Looks like you have a modern 3 channel timer. The thermostat beside it looks ok, it's a simple mechanical dial unit.

Do you have radiators in the hallway ?. If you have a thermostat in the hallway then you really need a radiator in the hallway. If I were you I'd try move the two other thermostats into a living room or a bedroom (make sure you remove the TRV in that room, or at least turn it fully up). Then the thermostat should control the temperature at the set point you chose (assuming the radiator is sized correctly). Hopefully the other rooms in the same zone will reach a similar temperature (but you can adjust them somewhat with the TRVs).

Sorry for the long winded reply.

Thats not really allowing for Opentherm Thermostats which are way more than a "Simple Switch"

They adjust Boiler Flow Temp depending on Heating Load and Temp Differential when connected to a compatible Boiler

So the Technology has definitely changed over the years

serox_21

Go with upgrading existing thermostats and timer plus zoning your house( if not already).

I upgraded a few months ago and it's a big difference.
If you don't want an internet controlled thermostat(nest or hive) then go with cheaper alternatives.

This is my setup for zoning, thermostats and magnetic filter:

Total for parts I think it was around 400euro

3x motorized valves around 45euro each(an old one was still working)
2 Salus RT510RF wireless thermostats (had one already) around 80 euro both
hot water cylinder thermostat 10 euro
bypass valve 17 euro
magnetic filter 110 euro