@derek-m yes- the pumps switch on and off. I felt each pipe getting warm, I think they all felt a similar temperature… We do find that downstairs heats up much quicker than upstairs though! Upstairs rarely hits the temp on the stats- only set to 18…
Hi Katie,
Because of Isaac Newton going and discovering gravity, water now insists on flowing downhill rather than uphill. 🙃
To counteract this problem, the designer's of UFH decided to fit flow control valves on each loop, these are the devices with the perspex top with a scale and a red marker.
To encourage the water to flow uphill rather than downhill, it is necessary to reduce the water flow to the downstairs loops by closing in the valves slightly. I don't know how well your system has been balanced, so I would suggest only closing each of the downstairs valves slightly at first. Make a note of the position of each downstairs valve, then adjust each one by approximately the same amount on the scale. This should reduce the flow to the downstairs loops and force more flow to the upstairs loops.
Once you have hopefully resolved your hot water problem by switching off the secondary pump, I can provide details of how to balance your system and set it for weather compensation control.
@derek-m thank you so much. The heating engineer is coming tomorrow so I am hoping he will agree to turn off the pump. can you advise where I open and close the valves from?!
@derek-m thank you so much. The heating engineer is coming tomorrow so I am hoping he will agree to turn off the pump. can you advise where I open and close the valves from?!
What is the manufacturer's name and model of the valves?
@derek-m thank you so much. The heating engineer is coming tomorrow so I am hoping he will agree to turn off the pump. can you advise where I open and close the valves from?!
Hi Katie,
The equipment is named TIO.
The flow valves appear to be adjusted using the black plastic ring below the perspex scale. Looking from the top, turn the black ring clockwise to close the valve and anti-clockwise to open the valve. See page 4 of attached manual.
@derek-m thank you for this. Probably a silly question but when the system is not asking for heat all the valve pressures are on 0… It’s when they are on that the pressure changes. I assume therefore that I adjust it when it’s on and asking for heat?!
@derek-m thank you for this. Probably a silly question but when the system is not asking for heat all the valve pressures are on 0… It’s when they are on that the pressure changes. I assume therefore that I adjust it when it’s on and asking for heat?!
Please explain what you mean by 'valve pressures'?
@derek-msorry- probably wrong terminology! In the Perspex scale. If it’s off the red ‘toggle’ is at the top on ‘0’ and when on it adjusts. I’ve attached a pic- 2 on left are off, 2 on right are calling for heat!
@derek-msorry- probably wrong terminology! In the Perspex scale. If it’s off the red ‘toggle’ is at the top on ‘0’ and when on it adjusts. I’ve attached a pic- 2 on left are off, 2 on right are calling for heat!
Hi Katie,
That makes a little more sense. Each device is a flow regulator/indicator, which I do believe have an operating range of 0 to 6 litres per minute. Without being able to clearly see the scale, I had assumed that the bottom of the scale would be 0 and the top of the scale would be 6, not the other way around.
To check and adjust your system, start by measuring and recording the actual temperature in each room, and then increase the thermostat setting by 1C in every room. The next step is to confirm that all the flow indicators are reading above zero, and record the reading of each one, noting its position. If any flow indicators are still showing zero flow, then locate the relevant thermostat and increase its setting by a further 1C.
The initial objective is to see how closely the weather compensation curve settings, match the actual heat loss, since the heat energy supply and heat energy demand of each individual room will differ. To do this, record the actual room temperature and indicated flow rate on say an hourly basis. If the actual temperature within a room increases to the point where the thermostat switches off the solenoid valve, and the flow rate falls to zero, this would indicate that the heat energy supply is greater than the heat energy demand for that particular room.
If, over time, all the solenoid valves are closed and all the flow rates are zero, this would indicate that the weather compensation curve settings are too high, producing a LWT that is warmer than required. If, on the other hand, only some of the solenoid valves are closed, hence reducing the flow rate to zero for those rooms, this would indicate that either the flow rate setting for those rooms is too high, or the flow rate setting for the other rooms is too low. I hope that makes sense to you.
The amount of heat energy being transported from your heat pump to your home, in basic terms, is a product of the LWT and the flow rate. So if it is possible to increase the flow rate, the same amount of heat energy can be supplied at a lower LWT. It is a proven fact that heat pumps are more efficient the lower the LWT, so this is the objective that one should try to achieve.
With your system, the aim should be to have the maximum flow rate to the coldest room, and reduce the flow rate to all the remaining rooms to achieve the desired temperature, whilst keeping the LWT from your heat pump as low as possible.
I would suggest that you carry out the tests detailed above, and identify the coldest room, which I suspect will be upstairs. Try increasing the flow to this room and see if the room temperature increases. Gradually increase the flow rate until there is no further increase in room temperature. Then repeat the process at the next coldest room. Work your way through all the rooms until you get to the warmer ones, where you may need to actually reduce the flow rate to achieve the desired temperature.
It will no doubt take some time to correctly balance your system, but I think you will find it quite beneficial in the longer term.
If the actual temperature is then too high in some of the upstairs rooms, you have the option of slightly reducing the flow rate, or use the thermostat to control the temperature. For maximum overall efficiency, downstairs temperatures should be controlled by your heat pump controller, by means of the weather compensation. Any temperature setbacks should, if possible, be achieved using the heat pump controller, but if this is not possible some other means can be used.
If there is anything that you don't fully understand then please ask for clarification.
@derek-m that’s fantastic- thank you. I will work on this over the coming days/ weeks and let you know how I go! Some of the rooms stats are wired up to the wrong rooms but should be sorted this weekend so that should make it a bit easier!
With regards to the DHW- I had the secondary pump disconnected this afternoon- I’m pretty sure it’s made a difference already to the heat loss in the tank, interested to see how it holds over night as it has been dropping 10 degrees.
It hasn’t resolved the issue of the temp of the hot water fluctuating upstairs though. I ran my son a bath- water luke warm (even though tank temp 50), put the hot tap on in the sink in the same room and it was freezing but it made the bath tap run hot!! Very strange… grateful for any suggestions? planning to get the plumber back out!
thank for all your help- be lost without this forum!!
@derek-m that’s fantastic- thank you. I will work on this over the coming days/ weeks and let you know how I go! Some of the rooms stats are wired up to the wrong rooms but should be sorted this weekend so that should make it a bit easier!
With regards to the DHW- I had the secondary pump disconnected this afternoon- I’m pretty sure it’s made a difference already to the heat loss in the tank, interested to see how it holds over night as it has been dropping 10 degrees.
It hasn’t resolved the issue of the temp of the hot water fluctuating upstairs though. I ran my son a bath- water luke warm (even though tank temp 50), put the hot tap on in the sink in the same room and it was freezing but it made the bath tap run hot!! Very strange… grateful for any suggestions? planning to get the plumber back out!
thank for all your help- be lost without this forum!!
Hi Katie,
It may be possible that the water flowing to your upstairs hot water taps is via the 'green pump' pipework rather than the pipework from the top of the hot water cylinder. Close one of the isolation valves, either before or after the 'green' pump. This may rectify the problem.
Where is the DHW temperature sensor located on the hot water cylinder? It needs to be fairly low down to ensure you get a tank 'full' of hot water.
@derek- thanks for the advice. I’ve turned the isolation valve off… hopefully that’ll do the trick! I’ll have a play with the position of the sensor- it’s currently quite high in the tank so can switch to the lower pocket 👍🏻
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