Room thermostat

Jimjay

In 2 bed terrace cl wood.
The room thermostat for central heating is by downstairs toilet door between front and back rooms. Anyone know where this is wired up to?
After 8 years I decided it didn't actually seem to do anything so decided to change it thinking it may be faulty at the same time changed it to a digital programmable one. Now odd thing is when the thermostat is turned off the boiler still comes on and when the thermostat is on the boiler turns on.

When we moved in to the house I had to wire up the timer clock on the boiler (separate to room thermostat) myself as the builders just left the wires disconnected so I have studied the wiring diagrams. Now next to where those wires go is spare space for a room thermostat to wire into to control the boiler but there is nothing going in to it. the room thermostat is wired with two brown cables (most places say there should be a brown and blue) the same cables do not wire in to the boiler anywhere.
Another strange thing is when the room thermostat (new and old) is activated there is a buzzing noise comes from the hotpress upstairs.

I do have an electrician booked to have a look but does anyone know what's going on?

Thanks

Cerco

Cannot be definitive on this but a possibility is that the thermostat is turning on/off a circulating pump feeding the radiators. When the room temperature reaches the thermostat setting , it turns the pump off. The boiler will continue to heat the water in the cylinder. When room temperature drops the thermostat will turn the pump on again thereby maintaining the room temperature.

Sir Arthur Daley

Jimjay wrote: »

In 2 bed terrace cl wood.
The room thermostat for central heating is by downstairs toilet door between front and back rooms. Anyone know where this is wired up to?



Another strange thing is when the room thermostat (new and old) is activated there is a buzzing noise comes from the hotpress upstairs.



Thanks

Your thermostat is activating a motorised valve, this is the noise you hear which is normal, the thermostat is wired to this motor valve.

Jimjay

WikiHow wrote: »

Your thermostat is activating a motorised valve, this is the noise you hear which is normal, the thermostat is wired to this motor valve.

Many thanks for your reply.

Can we get rid of the valve and have the thermostats wired to the boiler?
At the moment the program controls are useless as the thermostat cannot turn the boiler on or off. I was under te impression that the trrmostat measures the room temperature and activates a switch when the temp drops below a certain temp which then turns the boiler on. However i still have to turn the boiler off manually and the thermostat then has to be on to enable this valve in the hotpress.

I aslo wonder if the vavle is faulty anyway as the buzzing noise i mentioned can get very loud and can even wake you from sleep with two doors between.

Thanks again.

Charlie-Bravo

There should be a thermostat dial on the boiler - if the water returning to the boiler is hotter than the thermostat setting it will not fire the gas, but the pump will still circulate the water until the timer goes off.



Second dial from left - see the way it is half turned?!

Jimjay

astrofluff wrote: »

There should be a thermostat dial on the boiler - if the water returning to the boiler is hotter than the thermostat setting it will not fire the gas, but the pump will still circulate the water until the timer goes off.



Second dial from left - see the way it is half turned?!

Thanks. i have that set at the appropriate setting. According to the manual that sets the water temp between 40 and 80 degrees. it doesn't control the room temperature.
My main problem is that i want the room thermostat to turn the boiler on and off. it has a 7 day programmable multi temp timer on it. at the moment all it does it activate this valve in the hot press but when it clicks off the pump is still running on the boiler rather than turning it off. it can be wired in to the boiler easy enough, the same way as the timer built in to the boiler. I will have all the skirting boards off to change the floor so can run a new cable from the boiler. however can the valve in the hot press work without being attached to a thermostat.

Wonder why you got a different model of the boiler to us a few doors away :-)

Charlie-Bravo

But what about your domestic hot water? The idea of the Hall thermostat is to switch off the radiator flow and return, and continue to heat your hot water in the cylinder. What is your plan for heating the domestic hot water during say the summer months?

Jimjay

astrofluff wrote: »

But what about your domestic hot water? The idea of the Hall thermostat is to switch off the radiator flow and return, and continue to heat your hot water in the cylinder. What is your plan for heating the domestic hot water during say the summer months?

Maybe i don't understand. during he summer months we use the timer and switch in the hot press to heat the hot water for taps using the heating rod in the tank. Normally as we have our radiators on in the colder months we turn this switch to off and just let the boiler heat the water.

FirstIn

Isn't it better to use the gas to heat the water.

The stat on the wall outside the downstairs toilet controls flow to the rads. When the temp at the stat comes to the level you have set it to then it stops the pump/valve and thus the flow to the rads.

The gas boiler will keep running, cutting in and out to heat your water to the set temp, I believe set at the boiler.

During the summer I still use the boiler but just turn the stat downstairs to zero. Thus the rads don't heat.

Heating elements be it an immersion tank, kettle or bar heater consumes massive amounts of electric.

Jimjay

FirstIn wrote: »

Isn't it better to use the gas to heat the water.

The stat on the wall outside the downstairs toilet controls flow to the rads. When the temp at the stat comes to the level you have set it to then it stops the pump/valve and thus the flow to the rads.

The gas boiler will keep running, cutting in and out to heat your water to the set temp, I believe set at the boiler.

During the summer I still use the boiler but just turn the stat downstairs to zero. Thus the rads don't heat.

Heating elements be it an immersion tank, kettle or bar heater consumes massive amounts of electric.

Thanks for the info. Ok. So your boiler constantly heats the water in the tank to a set temp even when you dont need it?
How is that cheaper than running the element for an hour in the morning and in the evening. We only use the hot water to shower and wash up, we dont need the boiler to be permenantly running to keep the water hot. We only ever turn the boiler on with the on/off switch when we want central heating on.
Surely when the rooms have heated to the required temp it is cheaper to cut the boiler off rather than it continuing to heat the hot water that you dont need?

Again thanks for the info i am trying to get my head round this.

FirstIn

It only continues if you leave it on. Use the timer to control when you want it on and off. Or just override the timer and turn it on and off manually.

If you don't want the rads to heat turn the hall stat down. The gas boiler will then only heat water for the shower and taps. Just like turning the immersion off you manually turn the boiler back to the middle setting (i.e timer setting) when you want it off.

In the winter we normally leave the stat for the rads at 21. If we want hot water outside of the set morning and evening times I just turn on the gas boiler manually. The rads will heat also but you tend to want some heat in the house when you want hot water. If you like getting out of the shower to a cold bathroom you can certainly turn the rads off by turning the rad stat down.

Jimjay

FirstIn wrote: »

It only continues if you leave it on. Use the timer to control when you want it on and off. Or just override the timer and turn it on and off manually.

If you don't want the rads to heat turn the hall stat down. The gas boiler will then only heat water for the shower and taps. Just like turning the immersion off you manually turn the boiler back to the middle setting (i.e timer setting) when you want it off.

In the winter we normally leave the stat for the rads at 21. If we want hot water outside of the set morning and evening times I just turn on the gas boiler manually. The rads will heat also but you tend to want some heat in the house when you want hot water. If you like getting out of the shower to a cold bathroom you can certainly turn the rads off by turning the rad stat down.

Thanks.
I was hoping to use the advance features of the programmable thermostat but unfortunately it won't be an easy job to get to work properly with the way the houses here are done. Was hoping to use it for example if we go away we can either set it to keep a constant temp or to have the timer come on at different temps to say warm the house in the morning and then hotter in the evening etc etc without having the water constantly heating while the rads don't need to be on. i need some kind of dual control version where i can select the water to stay on or not if the room is at the desired temp.

Sir Arthur Daley

Jimjay wrote: »

Many thanks for your reply.

Can we get rid of the valve and have the thermostats wired to the boiler?
At the moment the program controls are useless as the thermostat cannot turn the boiler on or off. I was under te impression that the trrmostat measures the room temperature and activates a switch when the temp drops below a certain temp which then turns the boiler on. However i still have to turn the boiler off manually and the thermostat then has to be on to enable this valve in the hotpress.

I aslo wonder if the vavle is faulty anyway as the buzzing noise i mentioned can get very loud and can even wake you from sleep with two doors between.

Thanks again.

Ideally the thermostat controls the motorised valve and the motorised valve auxiliary contacts would turn on/off the boiler, it would appear your house should have been fixed fixed electrically to do this.

Jimjay

WikiHow wrote: »

Ideally the thermostat controls the motorised valve and the motorised valve auxiliary contacts would turn on/off the boiler, it would appear your house should have been fixed fixed electrically to do this.

Thanks. I think that is something like what my electrician said.
If i understood he said there would be two motorised valves and a separate hot water thermostat in the hot press. The room thermostat would activate the rad valve to turn the rads off and then when the water is at good temp the second valve should activate and in turn trigger a switch to turn the boiler off. Ideally with a dual control programmer to select if i want the water to be heated or not in the first place. Thats if i understand fully.

Sir Arthur Daley

Jimjay wrote: »

Thanks. I think that is something like what my electrician said.
If i understood he said there would be two motorised valves and a separate hot water thermostat in the hot press. The room thermostat would activate the rad valve to turn the rads off and then when the water is at good temp the second valve should activate and in turn trigger a switch to turn the boiler off. Ideally with a dual control programmer to select if i want the water to be heated or not in the first place. Thats if i understand fully.

Yea you are on the ball, the wiring should be there just to connect it up properly.

MiniGolf

Jimjay wrote: »

Thanks. I think that is something like what my electrician said.
If i understood he said there would be two motorised valves and a separate hot water thermostat in the hot press. The room thermostat would activate the rad valve to turn the rads off and then when the water is at good temp the second valve should activate and in turn trigger a switch to turn the boiler off. Ideally with a dual control programmer to select if i want the water to be heated or not in the first place. Thats if i understand fully.

What you are trying to achieve here is known as "boiler interlock"
Here is a good explanation:

Boiler Interlock:
This is not a control device but a wiring
arrangement to prevent the boiler firing when
there is no demand for heat. The boiler can be said
to be ‘interlocked’ when the boiler is switched ‘on’
and ‘off’ by the operation of a room or cylinder
thermostat (or a boiler energy manager). In many
cases the interlock will also apply to the pump
operation but any requirements for pump overrun
must be observed. Without an interlock, the boiler
is likely to cycle on and off regularly and waste
energy by keeping the boiler hot when it is
not necessary.
For regular boiler systems, the interlock is usually
arranged so that the room or cylinder thermostat
switches the power supply to the boiler (and
sometimes the pump) through the motorised valve
‘end’ switches.


From my experience in Charlesland the wiring is NOT present between the boiler and hot press to facilitate this arrangement. If the property was built before 2006 it would be eligible for grant aid towards the cost of the controls upgrade. There may be a wireless solution to this problem but I would have to examine the existing layout to confirm. If I remember correctly those homes have a motorised valve on the heating circuit controlled by a room thermostat and a thermostatic hot water temperature limit valve. There is no direct electrical connection between hot press and boiler. As stated earlier the timer on the boiler just fires the boiler and the boiler thermostat just controls the boiler temperature. NO interlock arrangement is present.

Jimjay

MiniGolf wrote: »

What you are trying to achieve here is known as "boiler interlock"
Here is a good explanation:

Boiler Interlock:
This is not a control device but a wiring
arrangement to prevent the boiler firing when
there is no demand for heat. The boiler can be said
to be ‘interlocked’ when the boiler is switched ‘on’
and ‘off’ by the operation of a room or cylinder
thermostat (or a boiler energy manager). In many
cases the interlock will also apply to the pump
operation but any requirements for pump overrun
must be observed. Without an interlock, the boiler
is likely to cycle on and off regularly and waste
energy by keeping the boiler hot when it is
not necessary.
For regular boiler systems, the interlock is usually
arranged so that the room or cylinder thermostat
switches the power supply to the boiler (and
sometimes the pump) through the motorised valve
‘end’ switches.


From my experience in Charlesland the wiring is NOT present between the boiler and hot press to facilitate this arrangement. If the property was built before 2006 it would be eligible for grant aid towards the cost of the controls upgrade. There may be a wireless solution to this problem but I would have to examine the existing layout to confirm. If I remember correctly those homes have a motorised valve on the heating circuit controlled by a room thermostat and a thermostatic hot water temperature limit valve. There is no direct electrical connection between hot press and boiler. As stated earlier the timer on the boiler just fires the boiler and the boiler thermostat just controls the boiler temperature. NO interlock arrangement is present.

Many thanks. My electrician explained the exact same to me today. As i am replacing the flooring and skirting boards at the moment i am going to trace a new cable from the boiler all the way to the hot press and have an installation put in just as you described. Not sure i will bother with grant as the cost after i get the cable in isn't a great deal.
Thanks again

tp25

Jimjay wrote: »

Many thanks. My electrician explained the exact same to me today. As i am replacing the flooring and skirting boards at the moment i am going to trace a new cable from the boiler all the way to the hot press and have an installation put in just as you described. Not sure i will bother with grant as the cost after i get the cable in isn't a great deal.
Thanks again

Yep, I'm doing very same at the moment, I'm running fresh wire through the attic, then next to the far corner of the attic and then down through the bedroom (behind the double wardrobes as one of the panes is easily removable.

You can do it behind the skirting boards as well.

If you have more money you can purchase wireless controllers (I don't bother).

you will create two zones, Ideally I wish to create 3 zones (perhaps later).

Sir Arthur Daley

What was the original idea by the electrician/plumber with this room stat?
Was it just powering down the motorised valve to the heating zone but not controlling the boiler?
If this is the case it was very badly planned out, the motorised valve auxillary contacts should have been used to control the boiler also.

tp25

the original idea was to cut the overheads, the length of the cable between 1st floor and the boiler would mean 15meters+ on average for each unit, then the controller at the boiler should be capable of being wired into the setup upstairs (this means more expensive controller).

This was very well planned to make owners uncomfortable, also it's a boost for local economy as wise owners would upgrade these from own pocket.

all planned... or at least part of it

Jimjay

WikiHow wrote: »

What was the original idea by the electrician/plumber with this room stat?
Was it just powering down the motorised valve to the heating zone but not controlling the boiler?
If this is the case it was very badly planned out, the motorised valve auxillary contacts should have been used to control the boiler also.

I think whatever the plans were the contractors did whatever was quickest and cheapest. Either that or some of them were not qualified for the work they were doing :-)

At the moment we have one thermostat. When the room is at the heat setting the valve to the rads closes and the boiler continues to heat the water tank (well at the least the pump continues).... Until you turn it off.

Cerco

Jimjay wrote: »

At the moment we have one thermostat. When the room is at the heat setting the valve to the rads closes and the boiler continues to heat the water tank (well at the least the pump continues).... Until you turn it off.

QED

Charlie-Bravo

Everyone is forgetting about the thermostat on the hot water cylinder - factor that into this so-called badly laid out design.

Sir Arthur Daley

astrofluff wrote: »

Everyone is forgetting about the thermostat on the hot water cylinder - factor that into this so-called badly laid out design.

And is there a motorised valve on the HW circuit that the tank stat switches off or does the tank stat switch off the boiler?

FirstIn

What about the water temp setting in the boiler itself? I'm confused.

My boiler doesn't continue to run indefinitely. It switches in and out. Firing I thought when the water in the tank gets below a certain set temp.

Charlie-Bravo

WikiHow wrote: »

And is there a motorised valve on the HW circuit that the tank stat switches off or does the tank stat switch off the boiler?

The thermostat is on the flow pipe with a probe inserted in the cylinder insulation, this stat turns off the flow through the calorifier. My only concern will be that once the ambient room temperature is reached downstairs (radiators), and then the cylinder reaches its desired temp, the pump will keep pumping water through a blocked circuit.

This is where my knowledge on central heating stops!

Jimjay

FirstIn wrote: »

What about the water temp setting in the boiler itself? I'm confused.

My boiler doesn't continue to run indefinitely. It switches in and out. Firing I thought when the water in the tank gets below a certain set temp.

Sure the gas fires on and off but the pump continues to run permanantly even if the valves are closed and there is nowhere to pump. Well ours does anyway.

At least with our new system we will be able to choose if we want the boiler to heat the water and rads or just one or the other and it will shut off the boiler including the pump when not needed. We will also be able to do full 7 day multi programming.

caesarthechimp

WikiHow wrote: »

Ideally the thermostat controls the motorised valve and the motorised valve auxiliary contacts would turn on/off the boiler, it would appear your house should have been fixed fixed electrically to do this.

This would prevent the gas boiler being used to heat the domestic hot water in summer though. In the summertime the original room thermostat should be turned down to zero. Then the boiler heats the water but not the rads.

astrofluff wrote: »

The thermostat is on the flow pipe with a probe inserted in the cylinder insulation, this stat turns off the flow through the calorifier. My only concern will be that once the ambient room temperature is reached downstairs (radiators), and then the cylinder reaches its desired temp, the pump will keep pumping water through a blocked circuit.

This has actually happened to someone. Boiler or pump makes a whining sound and eventually gives trouble. The plumber was called and he advised removing the probe from the cylinder insulation and just leave it loose. So the cylinder is always heating then, whenever the boiler fires. There may be some sort of bypass in the boiler which can deal with the excess pressure for a while, I'm not sure of that though. If there is, it doesn't work for everyone.

Jimjays solution is a Rolls Royce one, with interlock etc. but if anyone wanted a cheaper way of thermostatically controlling the boiler; leave the old room stat alone (as a way of separating the rads from the hot water in summer) but install a second one near the boiler, and have it interrupt the power supply to the boiler at the set temp.
Gas is less than half the price of electricity BTW, so its better for heating water.

domel

I got myself wireless room thermostat for less than 70E it switches on and off my boiler, anytime desired temperature drops down - works great!

Charlie-Bravo

Hi Domel, Can you give use some info on what it is? Make, model and how it integrates into your boiler system? Thanks.

tp25

domel wrote: »

next in line for the details of wireless room thermostat