Another Central Heating thread
Discussion
OK any plumber heating engineer experts out there?
A relative (aged) has had the central heating system updated. The back boiler ripped out and a combi boiler installed, new radiators bla bla bla.
The installer has not connected the system up to the room stat, and the boiler (Fontecal) also has the option of being connected to a temperature probe so that the automatic programme can adjust according to ambient temperature. It appears no such temperature probe has been installed.
What they have is that all the radiators bar the bathroom rad have thermostatic valves. It appears that the only control is the boiler temperature control on the pumped circuit.
The problem is that when the heating is on the circulation temperature is set at 70C, and so the bathroom gets like a sauna on speed!!!!
The only solution so far has been to turn down the circulation temp down to the minimum 50C, coupled with turning the heating on/off at intervals when the timed programme is not appropriate, at which point things are more bearable, but it still seems a bit crude.
The question is whether this installation ie no room stat or no temp probe typical and acceptable, or should I as a marginally competent relative give the installer a good shoeing? (metaphorically)
If this were in my house I could manage things by adjusting the circulation temperature according to ambient weather conditions, but this will be too complicated for the aged rellies.
A relative (aged) has had the central heating system updated. The back boiler ripped out and a combi boiler installed, new radiators bla bla bla.
The installer has not connected the system up to the room stat, and the boiler (Fontecal) also has the option of being connected to a temperature probe so that the automatic programme can adjust according to ambient temperature. It appears no such temperature probe has been installed.
What they have is that all the radiators bar the bathroom rad have thermostatic valves. It appears that the only control is the boiler temperature control on the pumped circuit.
The problem is that when the heating is on the circulation temperature is set at 70C, and so the bathroom gets like a sauna on speed!!!!
The only solution so far has been to turn down the circulation temp down to the minimum 50C, coupled with turning the heating on/off at intervals when the timed programme is not appropriate, at which point things are more bearable, but it still seems a bit crude.
The question is whether this installation ie no room stat or no temp probe typical and acceptable, or should I as a marginally competent relative give the installer a good shoeing? (metaphorically)
If this were in my house I could manage things by adjusting the circulation temperature according to ambient weather conditions, but this will be too complicated for the aged rellies.
Bathroom rads usually act as a heat sink to dump the excess heat/hot water to.
Kinda the same problem in my house, the system has thermostatics on all the rads except the bathroom. Does the job ok if we just manage the timing properly.
Like having a nice warm bathroom too, or just leave the bathroom door open!
Dave
Kinda the same problem in my house, the system has thermostatics on all the rads except the bathroom. Does the job ok if we just manage the timing properly.
Like having a nice warm bathroom too, or just leave the bathroom door open!
Dave
You only need thermostatic valves on the upstairs rads.
Just buy a digital programmable timer (with built in thermostat) from Danfoss or such (£20-£30), 2 or 3 wires, connect it to the switch on the boiler, and position the timer somewhere both convenient, and in the vicinity of the ambient temperature for the house.
>> Edited by parrot of doom on Tuesday 13th September 11:38
Just buy a digital programmable timer (with built in thermostat) from Danfoss or such (£20-£30), 2 or 3 wires, connect it to the switch on the boiler, and position the timer somewhere both convenient, and in the vicinity of the ambient temperature for the house.
>> Edited by parrot of doom on Tuesday 13th September 11:38
Sounds like a standard installation to me. Bathroom rads (as has been pointed out) are usually set to dump excess heat, and all other rads have thermostats so you can set each room temp individually - much better than a room stat in one place in the house. Your only option is to drop the circulation temp to a lower level. You'd usually expect not to have the heat on when your bathroom is already warm enough, but on ours we found that late summer and early spring were difficult to get right - we'd have the heating on and off all day. Usually we'd set the timer on the boiler to do half an hour on and half an hour off until the weather settled.
the room stat defo needs to be wired because without it,you effectivly can only have your boiler on or off by the programmer ie. its not doing its job properly .heating systems are meant to have control otherwise its back to the lighting a fire days.the stat controls the boiler bringing it on when cold and off once satisfied without you are banjoed..trv's fitted to all rads would not be good,because if they all closed the boiler pump would be pumping against a closed head so hence one rad is called a bypass this is normally the bathroom rad.the temp thingy as you called it could be an optimiser which reads air temp and alters the flow temp for max efficiency mostly not offered for domestic installations in the uk..so i would get him back to wire the stat in ,then normal control will resume
regards
guy
regards
guy
MARQUE said:
the room stat defo needs to be wired because without it,you effectivly can only have your boiler on or off by the programmer ie. its not doing its job properly .heating systems are meant to have control otherwise its back to the lighting a fire days.the stat controls the boiler bringing it on when cold and off once satisfied without you are banjoed..trv's fitted to all rads would not be good,because if they all closed the boiler pump would be pumping against a closed head so hence one rad is called a bypass this is normally the bathroom rad.the temp thingy as you called it could be an optimiser which reads air temp and alters the flow temp for max efficiency mostly not offered for domestic installations in the uk..so i would get him back to wire the stat in ,then normal control will resume
regards
guy
I think you're wrong - modern systems rely on stats on each radiator (they're required by law I gather). The boiler will switch off when the circulating hot water isn't dropping in temperature, which happens when all the rads turn themselves down. Ie. the boiler does cycle in response to demand.
Having a separate stat in a single room would mean that when that room got warm enough, the boiler would turn off and all the other rooms would stop being heated.
I could be wrong, but that's how our system worked.
Sorry for the hijack, but we have an 'issue' with our heating too.
We recently had the controller and a new 'change the direction of the hot water from rads to hot water cylinder' valve replaced as we were having probs with certain rads being on whether or not the heating was on via the controller.
We had a sky high gas bill for last year due to this and yet following the plumbing work detailed above (sorry for the dodgy explanation, but can't remember their technical names!), we still have 3 / 4 rooms that sit at 90F all year round!
Any ideas what the issue may be?
We recently had the controller and a new 'change the direction of the hot water from rads to hot water cylinder' valve replaced as we were having probs with certain rads being on whether or not the heating was on via the controller.
We had a sky high gas bill for last year due to this and yet following the plumbing work detailed above (sorry for the dodgy explanation, but can't remember their technical names!), we still have 3 / 4 rooms that sit at 90F all year round!
Any ideas what the issue may be?
Right - update following downloading tech info from manufacturer........
Turns out aged relly now remembers being advised to take up the option of the temp probe climatic control [1] but declined as a) don't trust new fangled doobry wossname thingies, mistake no 1 and b) assumed (you know what they say about assumed!!!!) that the device would be connected to room stat thus allowing a bit more control just like the old system. Mistake No 2, as room stat not connected for the very reasons outlined by Tuna above.
Now have to investigate retro fit of outside temp probe. Not eased by the 300 mile each way trip to visit.
[1] In case anyone is interested......
Basically systems are sized to work assuming an outside temp of -1C and of course most of the time they are oversized. When the temp probe is connected you set the device up by DIP switches based on the estimated thermal insulation of the building and reference to calibration curves within the installation/user instructions which I now have and were not left behind on installation.
What happens then is the temp probe measures the outside temperature and adjusts the circulation temp between 30C/80C to give a comfortable heating level and avoiding overheating and boiler cycling.
In answer to whoever hijacked, your problem sounds like when our motorised valve was up the spout and while I could see what was the problem convincing the BG 3-star engineer that his tinkering hadn't really solved the problem took a few call outs. New valve installed been fine since.
I would suggest that you do a few experiments. Let the system go clock cold. Turn on JUST the hot water system and see a) motorised valve position and b) check if some / all radiators get hot.
If so then a fault still exists. If you have an assistant it helps for one to operate the heating controls while one watches the valve operating to see what positions it adopts under certain settings and that the pump is working correctly.
Beyond that can't be much help, sorry.
>> Edited by Flat in Fifth on Wednesday 14th September 09:23
Turns out aged relly now remembers being advised to take up the option of the temp probe climatic control [1] but declined as a) don't trust new fangled doobry wossname thingies, mistake no 1 and b) assumed (you know what they say about assumed!!!!) that the device would be connected to room stat thus allowing a bit more control just like the old system. Mistake No 2, as room stat not connected for the very reasons outlined by Tuna above.
Now have to investigate retro fit of outside temp probe. Not eased by the 300 mile each way trip to visit.
[1] In case anyone is interested......
Basically systems are sized to work assuming an outside temp of -1C and of course most of the time they are oversized. When the temp probe is connected you set the device up by DIP switches based on the estimated thermal insulation of the building and reference to calibration curves within the installation/user instructions which I now have and were not left behind on installation.
What happens then is the temp probe measures the outside temperature and adjusts the circulation temp between 30C/80C to give a comfortable heating level and avoiding overheating and boiler cycling.
In answer to whoever hijacked, your problem sounds like when our motorised valve was up the spout and while I could see what was the problem convincing the BG 3-star engineer that his tinkering hadn't really solved the problem took a few call outs. New valve installed been fine since.
I would suggest that you do a few experiments. Let the system go clock cold. Turn on JUST the hot water system and see a) motorised valve position and b) check if some / all radiators get hot.
If so then a fault still exists. If you have an assistant it helps for one to operate the heating controls while one watches the valve operating to see what positions it adopts under certain settings and that the pump is working correctly.
Beyond that can't be much help, sorry.
>> Edited by Flat in Fifth on Wednesday 14th September 09:23
1. No radiator should ever, on a modern system, be used to 'dump' heat. Some combis include an automatic bypass within them and some require it to be fitted thereby allowing ALL rads to have TRVs.
2. It is still acceptable to fit all but one radiators with TRVs on a conventional system, BUT the remaining radiator should be in the space served by the Room Stat and the space which requires full temperature LAST, this is normally the Hall.
3. There are remote wireless stats available for around £50 if that solves any wiring problems??
4. HIJACK!! If you have a fully pumped system and some radiators are hot when the hot-water is on....it sounds like the radiator returns weren't commoned prior to their teeing into the boiler return. This would be on the original carcass so if it hasn't always done it it may be incorrectly wired. Worth bearing in mind that many 3-port fully pumped systems were 'Diverter' valves capable of CH or HW. Modern systems are most often 'Mid Position' allowing CH, HW and a bit of both. Replacing Diverters with Mid-Pos valves requires wiring modification to mke it work properly.
>> Edited by Ferg on Wednesday 14th September 17:24
2. It is still acceptable to fit all but one radiators with TRVs on a conventional system, BUT the remaining radiator should be in the space served by the Room Stat and the space which requires full temperature LAST, this is normally the Hall.
3. There are remote wireless stats available for around £50 if that solves any wiring problems??
4. HIJACK!! If you have a fully pumped system and some radiators are hot when the hot-water is on....it sounds like the radiator returns weren't commoned prior to their teeing into the boiler return. This would be on the original carcass so if it hasn't always done it it may be incorrectly wired. Worth bearing in mind that many 3-port fully pumped systems were 'Diverter' valves capable of CH or HW. Modern systems are most often 'Mid Position' allowing CH, HW and a bit of both. Replacing Diverters with Mid-Pos valves requires wiring modification to mke it work properly.
>> Edited by Ferg on Wednesday 14th September 17:24
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