Thermostat control in 1990s house

Johnnyq79

Hey,
Someone might be able to advise me regarding the above.
We have the oil boiler in the external shed, that is detached from the house. It’s an old one from when the house was built circa 1990. Newer firebird burner alright though. There is a thermostat dial on the boiler. Low, and 1-5. Problem is, I don’t think the low is low enough. When it’s on 1, the rads are still fairly hot. So, I don’t think it regulates very well. When it’s on 1, we end up turning off the switch again after an hour as it’s too warm.
In the house, we have rads upstairs and down stairs. The control switch is in the utlilty room. It just controls on, off and timer. We don’t have a thermostat within the house. Also upstairs and downstairs are not separated. It’s all or nothing.

What I would like to do, is put a thermostat in the house, to be able to adjust the temperature. Perhaps a smart one, ie Nest etc. I don’t know anything about these ‘Nests’.

Also, is there a simple way of separating the upstairs and downstairs, would that be thermostat valves on each rad?

I appreciate anyone’s help with this query.

Johnny.

Dardania

Heating controls would solve your problem easily there.

SEAI have grants for that: https://www.seai.ie/grants/home-grants/better-energy-homes/heating-upgrade-grants/

the principle would be exactly as you describe - a thermostat upstairs, and thermostat downstairs, and hot water cylinder control too. A plumber would need to fit electric zone valves to separate the boiler flow to each of these spaces.
If any of the thermostats in the zones call for heat, the individual zone valve would open, and the boiler would fire up.
The thermostat could be smart thermostat (e.g. nest) or not - as a minimum you should fit thermostats that have time control e.g. one these: https://www.heatingcontrolsonline.co.uk/room-thermostats-c-21.html/programmable-thermostats-c-21_31.html/hardwired-programmable-thermostats.html/danfoss-randall-tp5000-si-p-132.html or Nest if you want remote activation ability. That way, you can control what temperature you want, at what time, in each zone (e.g. downstairs at 20C for an hour in the morning + all evening, whereas bedrooms only on at bedtime etc.)
If it's difficult to find pipework to split the space heating between upstairs and downstairs, the alternative is to have a zone valve for space heating and a zone valve for hot water cylinder, plus individual TRVs on each radiator to control each room's temperature.

Regarding the thermostat dial on the boiler, it controls the temperature of water returning to the boiler - in practice using this to control the heat in the house is ineffective, as the radiators will by an large just emit heat when the boiler supplies it to them.

Johnnyq79

Dardania wrote: »

Heating controls would solve your problem easily there.

SEAI have grants for that: https://www.seai.ie/grants/home-grants/better-energy-homes/heating-upgrade-grants/

the principle would be exactly as you describe - a thermostat upstairs, and thermostat downstairs, and hot water cylinder control too. A plumber would need to fit electric zone valves to separate the boiler flow to each of these spaces.
If any of the thermostats in the zones call for heat, the individual zone valve would open, and the boiler would fire up.
The thermostat could be smart thermostat (e.g. nest) or not - as a minimum you should fit thermostats that have time control e.g. one these: https://www.heatingcontrolsonline.co.uk/room-thermostats-c-21.html/programmable-thermostats-c-21_31.html/hardwired-programmable-thermostats.html/danfoss-randall-tp5000-si-p-132.html or Nest if you want remote activation ability. That way, you can control what temperature you want, at what time, in each zone (e.g. downstairs at 20C for an hour in the morning + all evening, whereas bedrooms only on at bedtime etc.)
If it's difficult to find pipework to split the space heating between upstairs and downstairs, the alternative is to have a zone valve for space heating and a zone valve for hot water cylinder, plus individual TRVs on each radiator to control each room's temperature.

Regarding the thermostat dial on the boiler, it controls the temperature of water returning to the boiler - in practice using this to control the heat in the house is ineffective, as the radiators will by an large just emit heat when the boiler supplies it to them.

Thanks for all that.
We did a small extension in 2010 and the plumber that time couldn’t find the pipe to separate the zones. They dug a big hole but still couldn’t find it, so from I can understand the first option is not an option. Ie. Two thermostats-upstairs and downstairs. Smarts nests etc.

So it is just trvs on all the rads so?

Ubbquittious

Johnnyq79 wrote: »

Thanks for all that.
We did a small extension in 2010 and the plumber that time couldn’t find the pipe to separate the zones. They dug a big hole but still couldn’t find it, so from I can understand the first option is not an option. Ie. Two thermostats-upstairs and downstairs. Smarts nests etc.

So it is just trvs on all the rads so?

Trv is the easiest job, drain the system, horse them on, be grand.

Dardania

If you want SEAI grant, you need zone valve to separate hot water from rads circuit.
If that's a pain to find, then TRVs on all the rads + a tapstat valve on the cylinder will get good control, but won't be SEAI allowable. You can of course use a Nest with this configuration.

As Ubbquittious says, TRVs are great and relatively easy to fit if you had a clear run at it.

Johnnyq79

Dardania wrote: »

If you want SEAI grant, you need zone valve to separate hot water from rads circuit.
If that's a pain to find, then TRVs on all the rads + a tapstat valve on the cylinder will get good control, but won't be SEAI allowable. You can of course use a Nest with this configuration.

As Ubbquittious says, TRVs are great and relatively easy to fit if you had a clear run at it.

No chance of finding that pipe I’m afraid. We do have some kind of motorised value on the tank, so oil only heat water if temp is low. Solar panels heat the water. (Not in the winter though). Maybe that is what you refer to as the ‘tapstat’.

Didn’t think I could use the nest with trvs, so must look into that. Thanks. As I said I don’t have any existing thermostat, so no wires or anything. Can I still have a nest?

Plumber coming round to look at a dodgy rad soon so he might do the trvs for me at the same time.

Dardania

Johnnyq79 wrote: »

Dardania wrote: »

If you want SEAI grant, you need zone valve to separate hot water from rads circuit.
If that's a pain to find, then TRVs on all the rads + a tapstat valve on the cylinder will get good control, but won't be SEAI allowable. You can of course use a Nest with this configuration.

As Ubbquittious says, TRVs are great and relatively easy to fit if you had a clear run at it.

No chance of finding that pipe I’m afraid. We do have some kind of motorised value on the tank, so oil only heat water if temp is low. Solar panels heat the water. (Not in the winter though). Maybe that is what you refer to as the ‘tapstat’.

Didn’t think I could use the nest with trvs, so must look into that. Thanks.

Plumber coming round to look at a dodgy rad soon so he might do the trvs for me at the same time.

Not what I meant by tapstat - it’s a much simpler device compared to what you actually have. So definitely, combine TRVs with a nest and it’ll give you a very good solution. And should be SEAI compliant if you want to go down that road.

The principle with TRVs is they prevent individual rooms from overheating. And the Nest should be placed in a main living space to control the boiler on/off - for the rad in that main living area you shouldn’t fit a TRV.

Johnnyq79

Dardania wrote: »

Not what I meant by tapstat - it’s a much simpler device compared to what you actually have. So definitely, combine TRVs with a nest and it’ll give you a very good solution. And should be SEAI compliant if you want to go down that road.

The principle with TRVs is they prevent individual rooms from overheating. And the Nest should be placed in a main living space to control the boiler on/off - for the rad in that main living area you shouldn’t fit a TRV.

So by fitting the nest in the main living room, with not trv. Does that mean that this room will always the warmest room in the house? Two bedrooms upstairs face north and are cold out, so was hoping to have their rad on at a lower temp for longer.
So if I want the bedrooms on upstairs, I also have to have the living room at the ‘nest temperature’.
I think I’m confusing myself now

Dardania

Johnnyq79 wrote: »

Dardania wrote: »

Not what I meant by tapstat - it’s a much simpler device compared to what you actually have. So definitely, combine TRVs with a nest and it’ll give you a very good solution. And should be SEAI compliant if you want to go down that road.

The principle with TRVs is they prevent individual rooms from overheating. And the Nest should be placed in a main living space to control the boiler on/off - for the rad in that main living area you shouldn’t fit a TRV.

So by fitting the nest in the main living room, with not trv. Does that mean that this room will always the warmest room in the house? Two bedrooms upstairs face north and are cold out, so was hoping to have their rad on at a lower temp for longer.
So if I want the bedrooms on upstairs, I also have to have the living room at the ‘nest temperature’.
I think I’m confusing myself now

In general, people usually want the living room the warmest in the house, which is why they recommend putting nest there. You'd normally set the living room for 21C (as you're usually relaxing there, without heavy bedclothes) whereas in the bedrooms, they are normally set to 18C (a heavy bed clothes, and you need less heat when sleeping).
So in practice, while the boiler is trying to achieve 21C in the living space, the TRVs in the bedrooms are opening and closing as necessary to maintain a lower temp.

If you wanted to keep your options open, you could fit TRVs everywhere, and experiment by moving the Nest to different spaces to see where you get best control. Just whatever space has the nest, you set it's TRV to max temp, so that the Nest is in control of temp for that room. For a relative, I set their thermostat at the top of a landing, to get a good average temp for the house, with TRVs everywhere - seems to be working alright for them.