UFH not working for nearly a year

[Immokk]

I'm really hoping someone can help. I've not had downstairs heating that has worked properly for a year and no-one seems to be able to fix it. I know this is for self builds but I've read some posts and I'm just hoping someone can help. I'm a women (I think this matters as my contractor doesn't seem to hear me when I tell him things) and have been trying to get this resolved for months. It's kind of a long story and I may not be able to answer very technically but I am logical and ca. Show replies to my heating engineer I when he comes back. The story.

I moved into my home 5 years ago. House built 2004

There is UFH upstairs and down on two separate zones controlled by two different thermostats. One in the upstairs hall and one in the downstairs hall.

March 2018 the boiler was replaced for an Ariston ClasNet One. Reviews we're okay, warrantee long, my pockets not very deep.

Worked fine. Lovely toasty floors.

November 2019 downstairs manifold pump fails.

Engineer replaces it and, in the process, damaged a pipe with a tiny hole. Which he tries to repair.

Pump is successful. Lovely floors. Until the boiler cuts out as the pressure has dropped. The repair had failed and the damaged pipe was dropping over time, eventually leading to reduced boiler pressure. I topped up.

Engineer comes back. Tries to repair again. Still unsuccessful.

So up to now: new boiler is working. New pump is working. Damaged pipe needs to be replaced.

Engineer orders a new manifold section of pipe and it arrived. He realises it does not fit the old Thermostatic mixing valve and so orders a new one (Polypipe).

In February 2020 he fit the new valve and it briefly seemed like it worked. However, less than 2 weeks later the floors were cold in the middle and warm around the edges.

At this point Lockdown happened and I moved away to be with my partner. As it was March, I turned the heating off.

September 2020 I contact the engineer and ask him to come and look at the at the problem before Winter.

In October 2020 he comes out,drains water off to remove air. After which, though he is insistent he is getting good return temperatures, my floors are still not getting warm and my bills are extortionate as the rooms never get to temperature.

In December 2020 he replaces 3 of the actuator/ flow gauges (there are 5 downstairs loops all controlled by 1 thermostat only). The other 2, unbeknownst to me, he did not change as he had damaged the new ones. It appeared to work but less than 2 weeks later. Same problem. Warm edges cold middle. Cold house.

He came out. Couldn't fix it. Vanished.

I found someone else.

He has drained the system out using a cold tap with the system off. Got lots of air out. Filled each loop individually. Thought it was fixed. Less than a week later, progressively got to the same problem.

He came out again yesterday. Did it all again once going through from the cold water tap outdoors and once running through the boiler (?).

We did notice that the downstairs demand goes to the boiler and the boiler fires up but then after not long the flame icon on the digital panel goes off. After a while it comes back on again. Then off. Then on. This doesn't seem to happen with the upstairs manifold.

The floors are still cold.

The temperature gauges for flow and return on the manifold show just under 40c for flow despite him whacking it right open (expecting up to 60, similar to upstairs). I can hold the pipes in my hand, they feel luke warm.

Flow gauges are open.

I'm so sorry this is such a long explanation. I'll answer any questions I can if anyone thinks they can help. It's awkward to get to the manifold as it's under the stairs but I can try

Do you think there's a problem with the new mixing valve or something related to that, as it's only veen like this since that was replaced?

I'll take any help I can get. Thank you so much if you finished reading this.

[ProDave]

Hi and welcome.

 

The collective here will try and help.

 

A good start would be to post some pictures of your downstairs manifold, a general view showing all the pipes and anything else close by and then some close up ones of things like pumps, flow meters etc.  then we can talk you through some tests and observations to make.

 

It does sound as though you have had some incompetent people so perhaps mention your rough location and someone might be able to recommend somebody competent near you to have a look.

[Immokk]

Thank you. Just about to take a work call but have just crawled around and taken some pics and woll post thrm right after

[Immokk]

Hi all, over the next few posts please see some pictures of the manifold, the temp gauges (as they were after running for 3 hours today) and the pump/ thermostatic mixing valve.

 

Also attached a picture of the panel on the boiler. The little flame and bars in the centre at the top come on when demand hits the boiler and after less then 1 minute it goes off, I don't think it should do that and I don't believe it does that with the upstairs until temperature is reached, but as i say: I am really not an expert and I am at the end of my tether and a lot of money on engineers down the drain.

 

Just want to day the boiler was new in March 2019,has been serviced and I didn't have this problem (with the floors etc) until the mixing valve on the manifold was replaced.

 

As per ProDaves suggestion I am in South Staffs.

 

Thank you again. I'm honestly grateful for all help. I don't know what I'm doing but the engineers have been out 4/5 times, re commissioned, drained and still the problem persists.

Edited February 23, 2021 by Immokk
Typo

[ProDave]

Okay the obvious things.  When the heating is on, those red and white things on the bottom rail are flow meters. You shouls see a reading on them, as you do now, so water is flowing through all of the pipe loops at a good rate, so that also means the pump is working.

 

So next thing are the pipes hot or warm?  the bottom bar with the flow meters is the flow manifold and that should feel warmer than the top return manifold.  Both have a temperature gauge on them, what are those reading?  I can't see the scale from that picture but they look to have a high reading.

 

So at first glance, everything looks correct.

[Immokk]

https://www.dropbox.com/sh/qjb6brq1rbspjrb/AAAOjN83eTm4QGc2u3giiD-ra?dl=0

 

Thank you so much for taking the time. 

 

Here are more pictures (in drop box). And one below showing temps. Hope this works! 

 

The pipes when I felt were warm to touch but I could easily hold them and none were hot. 

 

The two temp gauges are similar temperatures for flow and return (the flow gets up to just below 40 although if you look at the mixing valve on one of the pictures, I feel like that's open to full, which I think is 60c)

 

Added info: the pump light comes on, when the demand is sent from the wall thermostat to the boiler, and the boiler kicks in, the flow gauges drop from the top (open)

Edited February 23, 2021 by Immokk
Added info

[SteamyTea]

18 minutes ago, ProDave said:

I can't see the scale from that picture but they look to have a high reading.

 

I zoomed in and seems to be about 40°C (bottom) and 35°C (top).

 

Looked at second set of pictures , 35 and 32

Edited February 23, 2021 by SteamyTea

[Immokk]

Yes, sorry it took so long to get the next set of pictures up. I had trouble with drop box. 

 

I think flow seems okay now (although I believe that was a problem before, there was definitely air when he first drained it a couple of weeks ago). That seemed to solve it for around 24 hours then over the next few days it just stopped getting the floors warm again.

 

I'm very sorry if this isn't as coherent as it could be. But I'm not an expert but I don't know where else to turn as the two separate engineers have been out a combined number of 5 or so times, charged me money and not fixed it. I will be calling second engineer back today but was hoping I might get some ideas from here

 

Attached picture is the boiler panel. That digital flame in the centre comes on when the demand is sent and the boiler first kicks in and then cycles off very shortly afterwards. When it first comes on it has 3/4 bars that drops to one (as you see) then it goes off. 

 

This system worked perfectly with this boiler until the pump valve was changed in February 2020 

 

[joe90]

10 minutes ago, Immokk said:

I'm very sorry if this isn't as coherent as it could be. But I'm not an expert

Don’t be, we are a very patient group here with lots of knowledge and understanding ?

[ProDave]

So water is flowing, you have a flow temperature of 35 and a return temperature of about 30.  So that all looks good.

 

If it is not heating the rooms properly, try turning the big black knob next to the pump anticlockwise a bit and try and get the flow temperature up to 40 degrees.  It will be a case of give it say a quarter turn then wait several minutes to see the effect on the temperature bottom flow temperature gauge and keep adjusting until you get it to 40.

 

I don't suppose you happened to notice what it was set to before you had all the issues and the mixer valve was changed do you?  What is the flow temperature on the upstairs UFH that appears to be working correctly?

 

Do you know anything about the ground floor construction? like is is a sold or concrete floor? what floor coverings etc?

[epsilonGreedy]

3 minutes ago, ProDave said:

So water is flowing, you have a flow temperature of 35 and a return temperature of about 30.  So that all looks good.

 

 

@ProDaveWhat do you think about the significance of the warm and cold zones in a single floor slab? Does the OP have a flow im-balance between different loops in the same room? 

[Immokk]

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!

[Immokk]

 

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

[ProDave]

60 (upstairs) is very high for UFH

 

My guess is the problem is just the temperature is too low to deliver enough heat, and I bet before changing the mixer, the old one was set much higher.

 

[Immokk]

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. 

 

[ProDave]

What are your floors made of downstairs?

[Immokk]

46 minutes ago, ProDave said:

What are your floors made of downstairs?

 

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

[SteamyTea]

2 minutes ago, Immokk said:

believe the floors are concrete beneath and:

Give it a few hours to warm up the cold concrete.

[Immokk]

30 minutes ago, SteamyTea said:

Give it a few hours to warm up the cold concrete.

 

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 ?

[SteamyTea]

1 minute ago, Immokk said:

spent the whole of winter with no heating

Apart from Christmas week, when I had an Aussie staying, so have I. But that is not unusual down here.

[Immokk]

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,

[SteamyTea]

Good.

So it may well just have been in need of a little tickling.

[Immokk]

2 hours ago, SteamyTea said:

Good.

So it may well just have been in need of a little tickling.

 

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.

 

Edited February 24, 2021 by Immokk

[SteamyTea]

You could ask a plumber to put in an automatic air bleeder.

 

I don't know enough about different pumps, but others do. Put up the make and model, then the plumbers can see if it is any good.

[Immokk]

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.