Immokk

Thank you so much @Onoff and @Nickfromwales That picture the top is the exact colour that was splattered around the inside of the mixing valve. I'm getting increasingly frustrated with my engineer (although I think he's a good guy): I asked him to install automatic air vents, he came on Wednesday with a new valve and no vents. Insisting it wasn't necessary. So @Nickfromwales no, I still have no vents. I'm so tired of fighting with them over this stuff. Apparently, despite all of the screwing around they've been doing they still know better. I am partially suspicious that he is not sure how to do it on my system and this is why he hasn't. I asked him to bring and use inhibitor. He said he would and on Thursday returned and, decided as the system was now working (at least for the time being) and there was nowhere to add it, he didn't feel like purging the system again in order to add the inhibitor was a good idea. He was convinced the muck was not corrosion etc and that it came from the old pump/ new pump when it was changed. He said it was the wrong colour (expecting black) Do you guys know how much a power flush should set me back? I'm exhausted with all of this and feel that I shouldn't have to press so hard to get the things I ask for done and yet, here I am, still faffing around. I'm totally okay to pay for it but don't want to be ripped off and it would be good to know what ball park I should expect. Thanks again for continuing to take the time to try to help me. EDIT: I only have UFH, no radiators.

Thank you for the reply. I don't know is the answer to 1 and as far as I'm aware he did not out inhibitor in. It's frustrating as i feel like everyone us doing a half a*** job on it! But I have heating right now... for how long, who knows.

So... when we took the Mixing valve off the manifold it was full of a reddy/ brown/ clay coloured sludge. We have no idea what it is or why it was in there and why it impacted the system to quickly after installation. The mesh inside the mixer was completely clogged up. The heating has been working since yesterday, the flow gauges are open well and they haven't closed off again (yet). I'm not convinced the centre of the floors are quite as warm as they should be but he think that's balancing so now we need to figure out which room is which on the manifold.

Just a quick update... he's on his way to fit a new valve. I am hoping he is also fitting the automatic vents as asked but I was a bit concerned he didn't sound too sure about them and aso, as you say @AliG , there are no spare ports so hoping he knows where they should go! I'll update tomorrow but hopefully that update will be that it is all sorted!

Yes it does! Immediately on changing the the temperature there is a noises, the flow gauges bob up and down then go back to just the one. I've been telling them that I've only been having the problem since the valve was replaced and the flow has been a problem since. It does improve immediately after getting air out but not for long. I've asked for the mixing valve to be checked and all they say to me is that the valves are basically never faulty. @Nickfromwales thank you for the advice and the tech term... the system is pretty old and I can't really afford to pay for someone to change it right now, especially with how much this ahs been costing me. You ask this: "Has the system been re-treated with inhibitor after / during each plumbers visits?" and my honest answer, is that I'm not sure. where exactly should the automatic air vents be placed so I can be very clear to my engineer.. then I can have him do both at the same time? I read yesterday they should be after the pump but there is obviously no space for that. You say on both bars... would it be at the ends? Thank you so much everyone. I think I need to insist on the valve being changed and ask for the air vents to be put in. I will keep everyone updated and lets hope it works. I can't tell you all how grateful I am. It's been... not fun.

Thank you for your answer He hooked a hose up to my outside tap and ran it out into the drain outside. So I assume he "drained" it in the respect that you describe above. It's odd that it works for a period and then the flow drops back down to 1 from 1.5-2 over 12- 24 hours. That flow is just enough to get warm floor in the tiny hall but other rooms are just too big for that it seems. Even the hallway floor will eventually stop warming. There is potentially still air but I don't know how he fixed that if he's spent the time doing what he's done. Perhaps the suggestion of doing that again and letting it run for a long time then installing an auto valve. I don't know enough to know if that will work or, indeed, can work on my system. It's pretty exhausting to still be having these conversations with the engineer after 3 months...

Hi there @epsilonGreedy yes, the warmth when its working quite well (but not properly) gets fairly close to he middle but over time that gets progressively worse and ends up being only the very edges but, specifically in the kitchen (as its tile and easier to tell). I'm fairly convinced it is air somehow as each time it's drained out and refilled through each loop, it works for 24 ish hours afterwards very well then progressively works less well over the course of a few days to a week until the floors are almost entirely cold. No-one seems to know why and I wonder if the previous suggestion of an auto air vent might help?

Thank you, here is a picture of the pump. Also set to 3. I do feel as though the pump is fine as once I had got the mixing valve to the 45 degrees the floors became beautifully warm. Seems there is something changing the flow over time. This is what happened last time too. Drained, refill loop by loop, warm floors for around 24 hours then gradually less warmth then basically no warmth across 2-4 days.

Unfortauntely, it seems my original problem remains. - Yesterday: adjusted the mixer to allow 45 ish degrees on the temp/pressure gauge - Over a period of a few hours temperature increased to 22c in the house - At 9pm I turned it from manual to auto. - Settings on wall thermostat are 20.5c during the day and to not allow temp to drop below 16c over night. - Mild weather meant that the house did not fall below either 20.5 or 16, and so the boiler did not kick in this morning. - At just after 9am, I switched to manual and increased temp demand on wall thermostat to 22c to see if the system was now working. - demand sent, boiler started, pump started BUT the gauges only 'dropped' to 1 or just under 1 (picture attached)... which will not be enough flow to keep my floors warm and after 2 hours, nothing has changed. Floors basically cold. - Yesterday when the floors were nice and warm it was 1.5-2. I just spoke to my engineer and explained the problem. Frustratingly, his response was first: "The guy from Ariston (boiler) said that perhaps the heating hasn't been wired into the boiler properly as two zones" - Obviously I challenged this. If that were the case it would never work. It worked last night without upstairs running (upstairs is set to a lower temp as I hate sleeping in the warm!) Then he said: "That's why I turned the mixer right down before I left, as the flow was decreasing when I turned it up so wanted to get flow through" - I then repeated that at 39c it wasn't sufficient outgoing temperature to run around the pipes within the loop and actually heat them. 45-47 seems to be the magic number and further to this, yesterday after I first altered it, it behaved correctly and worked fine. It was only after it shut down (as no heat required) and fired back up, the problem returned. Then he said: "I'll need to check the pump is the right one and is working" - To which I replied that if the pump was the wrong one then it wouldn't have worked yesterday. So, I feel that I am back to square one. There is clearly something throttling the flow. The system has been drained, running through cold water from an outside tap and into a drain, twice. And once through the boiler. After each time, it works (if the mixing valve is set art the right temperature). But then, over the course of a night, it stops again and the flow throttles. I should point out that on the first draining there was a lot of air, on the second there was air again but not as much. Any ideas? is air continually building up, and, if so, what might cause this? I have only been having this problem since the valve was replaced in February 2020 Is there a problem with the valve? I should add that it's unlikely there is a leak anywhere as the boiler pressure has not dropped in all the time since the valve was replaced.

Hi everyone, I wanted to give an update. So once the mixing valve was set and the temperature gauge on the flow went to just over 45c the floors felt warm (the kitchen particularly warm, as always, as it's tile). The other rooms warmed too and from about midday until 8pm the wall thermostat went from 15/16 to 22 (which is way hotter than it's usually set to but I had the thermostat on manual). It's quite mild out now, and overnight, so that only went down to 20.5 over night (my programme is set to 20.5) so it's not been on at all today. I am actually going to increase the demand for now to see if my old problem returns (the one I had for a year where despite being drained, over the period of a week, the floors stopped getting warm in the middle even if the system ran all day). I will post an update one way or the other so I can either a) get more advice if it happens again) or let everyone know if it's resolved, that way if anyone in the future has similar problems my thread with a resolution will exist. Thank you again,

Thank you, I will update later. I really appreciate people taking the time here. I've spent the whole of winter with no heating. I am hoping he has resolved the flow issue but left me with the mixer set too low ?

I believe the floors are concrete beneath and: - Tile, in the kitchen - wood (not very thick possibly even laminate) in every other downstairs room. Thank you again

Its at just over 40 and the floors are not warm (although, I would say, they are also not cold). Would you suggest: a) turning it up and getting temp to max and see the floors get hot (to ensure that is the problem) and then reducing down to 45-55? b) turning it a quarter turn and leaving it until my floors get warm or until it's at maximum and not warm (whichever it is?) I am hoping that the re-commissioning/ draining has solved the flow problems and that the engineer has just not put the temperature right on the valve.

UPDATE: I crawled into the space and first felt the pipes: 1) pipe into Manifold Mixing valve red hot 2) flow pipes, luke warm (barely warm at all) 3) return pipes were cold I then turned the knob as suggested, (bit by bit) and its now gone to 40 (and a return of around 35-36). I guess I wait a little now to see if anything heats up? (picture taken before I turn the dial/ knob around again, the next two turns got to 40) (p

Hi All, Thank you again. The upstairs was very high, from what i could gather (although the cover is back on right now, I think it was set to 55-60) I will try turning the black knob now and let you know what happens. Unfortunately, I don't know what it was set to before... it was a very different mixing valve too as was the original that was installed in 2003/4 Floors downstairs I believe, are concrete (but I can ask a neighbour to confirm, have never had the flooring up) Floor coverings downstairs are - tile in the kitchen, which always used to get beautifully warm (used to love wandering around in my socks!) and wood on the other downstairs floors (same again, used to get lovely and warm). Going to turn a knob!