DIY_Amateur Posted October 27, 2019 Share Posted October 27, 2019 Hi For the past couple of weeks I have been trying to get my new UFH balanced as per the instructions Uponor provide for the Compact V5. The final piece of the puzzle is calibrating the lockshield that is on the return of the manifold; to be clear this is a single lockshield on the return pipe not on the manifold ports. The instructions provided by Uponor are as follows: The lockshield valve needs to be opened so that it forces the majority of the water around the UFH system. The primary and secondary pump speeds, existing primary pressure and manifold size will affect how far open the lockshield valve needs to be. To make an adjustment first unscrew and remove the white cap. Use the included Allen Key to adjust the valve. To calibrate it is recommended that the lock shield valve is first fully closed and then opened until you see the thermometer continuously reading the same temperature as the setting on the injection valve head. I have followed these instructions as best I can but I never get the temperature on the thermometer to match the injection head it is always 5 degrees higher (ie I ask for 30 and the mixer provides 35) - thats the first problem. The second is that I can hear and feel the water flowing through the flow and return and I am mindful that the instructions say they want the majority of water to flow around the UFH but it seems like I get the occasional air lock so I end up opening the lockshield a little to release it. Perhaps I am just being to cautious and it needs to be a little more open (and maybe that will fix my first problem too) but for something described as calibration the instructions are rather unhelpful; some description of what happens when it's too closed and too open would help me determine the right setting. Does anyone have any experience of calibrating this manifold and any words of wisdom please? Thank you Link to comment Share on other sites More sharing options...
scottishjohn Posted October 27, 2019 Share Posted October 27, 2019 I,m sure someone will come along to help --pictures of manifold might be helpful-- maybe your air lock is caused by pipe runs ? Link to comment Share on other sites More sharing options...
Triassic Posted October 27, 2019 Share Posted October 27, 2019 1 hour ago, DIY_Amateur said: I have followed these instructions as best I can but I never get the temperature on the thermometer to match the injection head it is always 5 degrees higher (ie I ask for 30 and the mixer provides 35) - thats the first problem. My old system was the same, the two temperatures never matched. I wouldn’t loose sleep over this. Link to comment Share on other sites More sharing options...
DIY_Amateur Posted October 27, 2019 Author Share Posted October 27, 2019 Thanks for the quick replies, I've attached a pic from the manual so most of the parts are labelled. Also a picture of my system with the allen key in lockshield and the thermometer vs injection head. @Triassic I have leaning towards your view that these are a guide rather than exact values, I'm just mindful that my flooring type will be vinyl tile and the floor temperature needs to be very low (<30 degrees) so I am not sure which of the two things to trust. Maybe I need to an IR thermometer to check? Uponor seem unique in putting this lockshield on their manifold so it's hard to find much about this on the web. I appreciate all replies, thank you! Link to comment Share on other sites More sharing options...
scottishjohn Posted October 27, 2019 Share Posted October 27, 2019 you have an AAV on system --to bleed out any air? Link to comment Share on other sites More sharing options...
DIY_Amateur Posted October 27, 2019 Author Share Posted October 27, 2019 Yes, there's an AAV on the return just out of shot to the left of the allen key, there's also one on the flow from the boiler Link to comment Share on other sites More sharing options...
ProDave Posted October 27, 2019 Share Posted October 27, 2019 That is a very different mixing system to any other sort of UFH manifold that I have ever seen. A "flaw" in this calibration procedure is they are making the assumption that the setting dial on the input thermostat is actually calibrated correctly and you will therefore see exactly that set temperature on the thermometer. I would not trust that to be the case, especially at low temperatures. As long as you are seeing a constant temperature on the thermometer, and that constant temperature goes up and down as you adjust the input thermostat (allowing it time to do so when you make an adjustment) then I would not worry. Then set the temperature to get the thermometer reading the temperature you want, and ignore what the dial on the thermostat says. The principle of operation here is the thermostat head will shut off the boiler flow when the set temperature has been reached. What source drives the UFH is it a boiler or a heat pump? Link to comment Share on other sites More sharing options...
DIY_Amateur Posted October 27, 2019 Author Share Posted October 27, 2019 (edited) Hi Dave - thanks for the reply. I have a oil boiler supplying the heat. I'm pretty sure the temperature moves in the right direction when I move the thermostat so the manifold seems to be responding correctly. Out of interest how do other systems control how much water gets sent back to the boiler and how much gets recirculated round the UFH pipes? Edited October 27, 2019 by DIY_Amateur Link to comment Share on other sites More sharing options...
ProDave Posted October 27, 2019 Share Posted October 27, 2019 My mixing system looks like this That was obviously before the pipes were connected. The two ports to the left of the temperature dial, the top one is boiler return and the bottom one is boiler flow. Most that I see are a variation on this type. But neither is right or wrong, just different. I asked about the source as I found mine would not reliably regulate low enough so I have it set as low as it will go and instead regulate the temperature by setting the "water leaving temperature" on the air source heat pump to deliver the water temperature that I want. I think your type of thermostat with a capilliary sensor regulates better. Link to comment Share on other sites More sharing options...
PeterW Posted October 27, 2019 Share Posted October 27, 2019 6 hours ago, DIY_Amateur said: Out of interest how do other systems control how much water gets sent back to the boiler and how much gets recirculated round the UFH pipes? The blending valve controls it. When the floor starts off, the blending valve will demand more hot than recirc as the return temp will be 15/16c and the demand will be 35c so the boiler will be providing a lot of the heat. As the return temperature increase then the amount returned to the boiler starts to reduce, and this is where the boiler will start to short cycle if you’re not careful. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted October 27, 2019 Share Posted October 27, 2019 We have exactly the same thermostatic valve system, with a remote capillary sensor that fits in the flow manifold. Two things I've discovered are that the calibration of the valve head is pretty rough and ready and the dial-type thermometers are very inaccurate. I've looked around in vain for anyone that stocks replacement thermometers, in the hope that I can find some accurate ones. In the end, I just stuck self-adhesive liquid crystal temperature measurement strips to both manifolds. Not easy to read, but they do seem to be consistent with each other. The ones I bought have a scale that runs from 18°C to 34°C, in 1° steps. 1 Link to comment Share on other sites More sharing options...
DIY_Amateur Posted October 27, 2019 Author Share Posted October 27, 2019 Thank you everyone for the replies. I've ordered an IR thermometer and some strips so that should help. I'm still not sure how to set the lockshield but if I can find the sweet spot where it is sufficiently open that no airlock occurs then I suppose that's the best I can do. But if anyone reads this who has set up an Uponor of this type I'm very interested in your experience! Thanks again Link to comment Share on other sites More sharing options...
DIY_Amateur Posted October 28, 2019 Author Share Posted October 28, 2019 I wasn't sure whether to start a new thread but I have a follow up question... My under floor serves two rooms each with 2 loops; one half was existing when I bought it and the other is new underfloor that I have installed. I can't run the new bit as it's new screed and I'm letting it dry out but the old section has been down for years. Last winter (before putting in the new section) I noticed the room took an age to warm up and it never really felt like it was doing more than 'taking the edge off'. I hoped it was a fault with the old manifold and that new manifold if set up properly would sort it but now I am not so sure. Last night I left the system on and set to 19degrees (no set back or anything), I checked it as various times and by 1am it had fallen to 18.2 and stayed there until at least 4am. It's now 9:30am and it's only risen to 18.6. The room measures 35sqm and the flow rate is 3l/min and the thermometer claims the water is 35 degrees on the mixer; the flow temp to the manifold is very hot probably 70degrees. I have no way of knowing how closely the pipes are laid but I can see that there is some insulation under them and the screed is approx 70mm, when my IR thermometer comes I guess I can try figuring out the pipe runs under the tile floor to check spacing. Appreciate it's hard to diagnose but does this sound right, are my expectations too high? Thank you Link to comment Share on other sites More sharing options...
JFDIY Posted October 29, 2019 Share Posted October 29, 2019 You'd expect it to be able to heat the space to 22c especially as it's not even freezing outside, but it depends on what the original design was based upon, was it bedrooms? These have a lower temperature expectation and the pipe spacing might be wider on that basis. I'd consider raising the temperature to even 45c but depends on the construction and finish covering. Is the space you're heating confined, i.e. you haven't taken a dividing wall out and in reality trying to heat 70m2 with only 35m2 of pipes. Measuring the supply and return temp of each loop will a the clue to what is going on, might find all the heat is being absorbed by the screed and the flow needs increasing. Link to comment Share on other sites More sharing options...
Triassic Posted October 29, 2019 Share Posted October 29, 2019 (edited) 21 hours ago, DIY_Amateur said: Last winter (before putting in the new section) I noticed the room took an age to warm up and it never really felt like it was doing more than 'taking the edge off'. UFH isn’t designed to give a rapid response. It’s the sort of setup that takes hours to get to a working temperature, you leave the boiler running and let the room stat call for heat as and when necessary. Edited October 29, 2019 by Triassic Link to comment Share on other sites More sharing options...
dpmiller Posted October 29, 2019 Share Posted October 29, 2019 3l/min isn't very much surely? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted October 29, 2019 Share Posted October 29, 2019 4 hours ago, dpmiller said: 3l/min isn't very much surely? Enough to deliver about 1.045 kW of heat with a temperature differential between flow and room of 5°C. We run our three floor loops at ~2.5l/m each, with a temperature differential of ~2° to ~3°C, so in total the UFH will be delivering between ~1 kW and ~1.6 kW when running. Link to comment Share on other sites More sharing options...
DIY_Amateur Posted October 30, 2019 Author Share Posted October 30, 2019 Thanks for all the replies. I don't think the system will go above 3l/min and it's meant to auto balance the loops although I've seen no evidence of it doing that as the actuators just appear to be either fully on or fully off. No changes have been made to the layout of the room so it's as the previous owner built it but I don't know pipe spacing and I have no idea how much effort went into working out the heating requirement of the room. I suspect not a lot! I have checked the floor surface temperature and it seems to be heating to around 25 degrees and the mixer is around 27-29. The room stat is set to 19 but I've also checked that against another couple of thermometers and it appears to be 1.5-2degrees too low ie I set it to 19 but it's trying the heat the room to 20.5-21. I would try 45 degrees but I am constrained on the mixer temperature as one room is tile so could take a higher water temperature but the other is going to be vinyl tile (the screed is new so it's still drying and not being heated), since I can only have one mixer temperature it has to be set low because it will be serving the vinyl tile floor and that can't be above 27 degrees. I will have a go at measuring flow vs return temperature differential on the plastic pipes to see what that shows. For the past week I have given up on having any kind of set back temperature so it's been on 24/7 at 19 degrees (20.5-21 actual) and whilst I know it's slow to respond I just didn't expect it to struggle 7 days in when the first cold-ish night arrived. All in all I have to say I am underwhelmed by the whole UFH experience and yet I know many people can't speak highly enough of it so I will persevere (I don't have much choice) but I appreciate all the comments and experience of others as the information helps me compare and maybe rebase my expectations. Thank you! Link to comment Share on other sites More sharing options...
Zed Posted October 30, 2019 Share Posted October 30, 2019 If you realistically envisage having to run at higher temp at the room awaiting flooring, specify the high temp adhesive, the epoxy resin stuff , for the amtico/karndean , then you won't be constrained to 27 max. Fitters will try to talk you out if it because it's more difficult to lay with, but stops you worrying about £1000's of flooring potentially lifting if you need the higher temp. Link to comment Share on other sites More sharing options...
Ed Davies Posted October 30, 2019 Share Posted October 30, 2019 @DIY_Amateur, have you said what sort of insulation and airtightness levels your house has? Link to comment Share on other sites More sharing options...
DIY_Amateur Posted October 30, 2019 Author Share Posted October 30, 2019 Thanks Zed - interesting about the high temp epoxy I'll have to find out about that, thank you for mentioning it. Ed - the room in question is about 15-20 years old and although I don't recall if it has building regs it appears to have been built to a good standard. The window are double glazed (<10mm gap between panes) and don't leak but you do notice the cold when stood by them, the UFH/screed is laid on insulation, looks like polystyrene but I don't know what thickness, the room is exposed on three sides and has a vaulted ceiling (which is insulated with celotex at a guess 80-100mm), so I am aware that it has some challenges. I know it's hard to guess but assuming a reasonable standard of construction should UFH be ok for a room like this? Link to comment Share on other sites More sharing options...
JFDIY Posted October 30, 2019 Share Posted October 30, 2019 Couldn't you put a floor temp sensor in to limit the vinyl areas surface temp, then run the remainder at a higher temp to heat the room your concerned with now, seems a heck of a compromise to not be able to get into the 20c region when it's still +8c outside Link to comment Share on other sites More sharing options...
DIY_Amateur Posted October 30, 2019 Author Share Posted October 30, 2019 Hi JFDIY - That sounds like it has potential, is a floor temperature something that can be retrofitted? Thanks Link to comment Share on other sites More sharing options...
JFDIY Posted October 30, 2019 Share Posted October 30, 2019 You might need to talk to the supplier of your controls, but it looks do-able as a retro-fit. I've yet to get into the detail as I'm not that far on yet. See this Wundafloor video as an example Link to comment Share on other sites More sharing options...
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