Go to Forum Home Building Services Room thermometers

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    • #31768
      Anonymous

        I'm having issues with the heating system in the new house, some rooms never seem to stop calling for heat (I think) regardless of temperature, I was thinking of getting a few thermometers to dot around the house to see what's actually going on but how accurate are they?

        Lot's of cheap ones about on eBay but no idea on accuracy, I guess as a minimum they all need to read the same temperature in a particular location.

        Any advice appreciated

      • #38791
        Anonymous

          I'm having issues with the heating system in the new house, some rooms never seem to stop calling for heat (I think) regardless of temperature, I was thinking of getting a few thermometers to dot around the house to see what's actually going on but how accurate are they?

          I don't remember how your heating system is designed or constructed. What is calling for heat in each room? And how do you observe that?

          Lot's of cheap ones about on eBay but no idea on accuracy, I guess as a minimum they all need to read the same temperature in a particular location.

          Accuracy doesn't matter too much; repeatability is more important. If you know that one thermometer always reads half a degree low, or a full degree high, you can compensate. Also, if you buy several of one type, you can compare the readings from them all. You could always use a better thermometer to calibrate them, of course. I recently bought some of the cheap temperature+humidity units, and they're OK for the money.

        • #38792
          Anonymous

            I don't remember how your heating system is designed or constructed. What is calling for heat in each room? And how do you observe that?

            2 zones (ground and first) room thermos in each, I went for a simple dial based one, no digital readout. There's a red LED that lights up to show it hasn't reached the required temperature.

            Accuracy doesn't matter too much; repeatability is more important. If you know that one thermometer always reads half a degree low, or a full degree high, you can compensate. Also, if you buy several of one type, you can compare the readings from them all. You could always use a better thermometer to calibrate them, of course. I recently bought some of the cheap temperature+humidity units, and they're OK for the money.

            Yup, I was thinking similarly. The humidity ones are v cheap.

          • #38793

            Why is a new house designed other than with typical continental controls of weather compensation and continuous heating?

            Compulsory across the Channel, so rare here that some heating installers don't understand the concept.

          • #38794
            Anonymous

              Ours is almost clueless on how it's supposed to work.

            • #38795
              Anonymous

                Why is a new house designed other than with typical continental controls of weather compensation and continuous heating?

                Does it still make sense if there is a thermal store between the heat source (perhaps boiler) and heat distribution?

                Also, if it's UFH, is the temperature not controlled by controlling the floor temperature to very slightly above the desired room temperature? External temperature would mainly affect the frequency of boiler firing, I suspect, although could be used as a second-order factor for the floor setpoint.

              • #38796

                Tariq

                Weather compensation is explained by these installers ecotechnicians.co.uk. If you're near enough to London where they're based it might be worth paying one to visit and do some fine tuning or even suggest modified controls for a condensing boiler which should be run with low water temperatures 24/7 not as hot as possible for two periods/day.

                Or I know a retired mechanical engineer in Essex if any use but he'd similarly want a consulting fee to sort out someone else's heating system (He achieves a measured 96% efficiency using a condensing boiler on the existing radiators).

                It should be more valuable with UFH. Without it there tends to be a regular fluctuation in room temperature. caused by too much heat entering the floor at once.

                Surely a condensing boiler shouldn't need a thermal store for the space heating. Gas can be burned very precisely on demand, as the bills from well-designed and installed systems all bear out although it would ne nice if they were the rule not the exception.

                David

              • #38797
                Alan Clarke
                Participant

                  Tahir
                  are the thermostats indicating they are calling for heat, ie showing the red LED, even when the room is warm (and room temperature dial turned to minimum)?
                  If so then check for accidental setting of the floor sensor to a minimum temperature rather than a maximum (the setting for this is hidden under the cover of the room stat).

                  or is the floor warm even when the thermostat is not calling for heat?
                  if so, then either a wiring fault or the actuator is not fitted to the manifold valve correctly.
                  Can you turn off power to the contoller for the relevant manifold and wait a day (with heating on) – I think the actuators are power-to-open so if the floors in question are still warm then the actuator isn't closing the manifold valve.
                  if removing power to the manifold controls does cut heat to all zones, the controls electrician needs to come in with a voltmeter (and the uponor manual) and work out what isn't connected properly.

                  David
                  the boiler has direct weather compensation – was set at a curve of 0.4 I think, ie boiler should be running around 30C.

                  Alan

                • #38798
                  Anonymous

                    Tahir
                    are the thermostats indicating they are calling for heat, ie showing the red LED, even when the room is warm (and room temperature dial turned to minimum)?
                    If so then check for accidental setting of the floor sensor to a minimum temperature rather than a maximum (the setting for this is hidden under the cover of the room stat).

                    Yes, they'd done this on some rooms, the ones with the wooden floors, caused some interesting shrinkage. They said they'd adjusted them all now so that they were set to maximum rather than minimum. I could check again.

                    or is the floor warm even when the thermostat is not calling for heat?

                    It does feel like it in some locations

                    if so, then either a wiring fault or the actuator is not fitted to the manifold valve correctly.
                    Can you turn off power to the contoller for the relevant manifold and wait a day (with heating on) – I think the actuators are power-to-open so if the floors in question are still warm then the actuator isn't closing the manifold valve.
                    if removing power to the manifold controls does cut heat to all zones, the controls electrician needs to come in with a voltmeter (and the uponor manual) and work out what isn't connected properly.

                    It's difficult to judge how hot/cold the floors are, especially with different floor coverings; solid timber, engineered cork, concrete, it's very subjective.

                    Another issue I raised with them was the patchy nature of the heat in the concrete floor at the junction of the hall/kitchen, according to them it was where all the different manifolds are routed out, so some may have been calling for heat and others not.

                  • #38799
                    Alan Clarke
                    Participant

                      Tahir
                      back to thermometer question, if you just want to monitor air temperature then £5 digital thermometer from Maplin will do – typically claim 1deg C accuracy but 0.1C resolution. If you get several then put them together first to check the readings agree, they are usually much closer than 1degree. I don't think cheap rh measurement is worth it – seems quite inaccurate – not always within 5% in my experience.
                      But for seeing if a floor is being heated or not then £30+ for an IR thermometer is more what you need.
                      Alan

                    • #38800
                      Anonymous

                        OK, so I might go for some cheap room thermometers and an IR one, might be useful to someone here afterwards?

                      • #38801
                        Anonymous

                          Cats? On AECB? It's surely not environmentally friendly to keep cats, all that extra food, all those poor dead birds, worse than kids aren't they?

                          Anyway, most of the ones I've seen on eBay seem to be accurate to within +/- 2C, is that worthwhile?

                        • #38802
                          Nick Grant
                          Participant

                            Tahir

                            Agree with Alan. If the floor feels warm then it is what I'd call hot! Your floor won't be much above room temp when on so will feel cool to touch. The medium price IR thermometers from Maplin are fine. Resolution good, 0.2C or so and you can 'calibrate' against a surface at room temp.

                            Can also check kids for fever at a distance if you suspect they have something you might catch!

                            Nick

                          • #38803
                            Anonymous

                              Plumbers are back on site this morning, unfortunately I'm not, so they're wandering around with their IR thermometer, they say that floor temperature is 17-18C in most places. Room thermos turned up yesterday so will start investigating tomorrow

                            • #38804
                              Mark Siddall
                              Participant

                                Cats? On AECB? It's surely not environmentally friendly to keep cats, all that extra food, all those poor dead birds, worse than kids aren't they?

                                Anyway, most of the ones I've seen on eBay seem to be accurate to within +/- 2C, is that worthwhile?

                                Cats seem to be accurate to within +/- 2C?

                              • #38805
                                Anonymous

                                  One of the bedroom floors is 2C cooler than the others, this is very noticeable. Will speak to the plumbers.

                                • #38806
                                  Nick Grant
                                  Participant

                                    In terms of measuring floor temperature, this is what it might look like under long wave IR. Area average temp 17.7C.

                                  • #38807
                                    Anonymous

                                      So I need to be v accurate with where I'm taking a reading. Noted, will try and work something out. Plumber was back yesterday he's adjusted the flow rate to that room.

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