vala

Does anyone here have any recommendations for contractors to complete a polished concrete floor? I'm based in Milton Keynes. Thanks

yeah, it'll be the same builder so sure he'll some idea when he does the first part. Tiny, 9sqm. Literally just for a downstairs loo.

no idea on this yet. first thing is to get the shell of the extension done. Hopefully he fits us in this year, then once the weather warms up next year we'll have the slab in the house sorted.

builder mentioned it when we were discussing floor build up due to the UFH. not set on using it, just looking at other option and then will discuss with him. if we can lose the mesh then great, and can then just clip the pipe work to the PIR. slab is only circa 55sqm.

Should be starting a little extension which will form part of the UFH on the ground floor. Plan is to have the existing slab taken up, dug down, insulation and a new slab with UFH within. Plan is for the finished floor to be polished concrete but just the 'cream' standard. I need to discuss with the builder but from info I've read on here and other sources, I thinking of a baseline to be: hardcore compacted, sand binding, 200mm PIR, UFH on mesh, 100mm concrete slab. Would this be ok? Or should I be looking into other thicknesses of concrete, different amount of insulation, different insulation, UFH clipped onto PIR instead of tied to mesh, etc etc? Any help would be much appreciated.

Had the existing CWI surveyed after being in touch with CIGA. Did suffer a bit of mould in the corner of a room and the house didn't ever get to its targeted temp. Assumption was that as the heat was rising is was leaking quicker. The survey highlighted a few areas where the mineral wool wasn't in place and also when I have changed the windows on the first floor the cavities were quite sparse. And yes apologies, I meant R values. I'm not as clued up with the impact of R values so although it may appear to be a minor increase it may actually be quite something, again though I have little knowledge on whether this is true. I spoke to Polypearl regarding the difference and they didn't give a reason or advise on what product due to the make up of the house. And the 2 installers they recommended, one only installs Plus, the other only Platinum.

Hi all. Had some quotes for CWI. Polypearl plus is £2700, Polypearl platinum is £4300. Both quotes include extraction of the old mineral wall. Can anyone advise if the platinum is worth the extra £1600? The difference between the 2 u value's is 0.005.

Had an inspector out to check if we had CWI and if so what's state its in to know whether to change it or not. From his report back, he notes our cavities are in the region of 70mm, yet he did mention on the inspection day some areas were down closer to 55-60mm. The type we currently have is Insta fibre/white wool. He notes that there are a few voids and I've seen first hand there are gaps/voids when I installed the first floor windows. So think we'll need to have the lot replaced. Have spoken to Polypearl who recommended an installer who has offered Polypearl Plus, didn't really give any real reason as to why not go with Platinum even though he does offer it. Also spoke to Polypearl who have said there Platinum offers 25-30% improvement over Plus. He didn't give any details as to what effects the extra performance, I assume bigger cavities would help. With my home having between 55-70mm, would I really benefit?

Apologies for the delay I’m replying. No still not sorted. Have resorted to just using the manual actuators for now. Tbh when we had that cold snap in December it highlighted the CWI that apparently has been fitted (says so on the last 2 EPC reports) is not very good. This has resorted in one room in particular that struggles to get up to temp when the cold weather is present (1-2° and colder temps). So looking into getting that sorted along with the ground floor works which will include wet UFH throughout. Then we’ll get back onto trying to use the ABA’s.

We used Wilson ThermalStream. It’s 10mm thick.

I recently spoke to PolyPearl who put me in touch with an installer for CWI. The installer noted that there may be a grant being available in the near future for this? Has anyone else heard of this? I done a google and the only grants I could find were relating to those being available a while ago.

No problem. I'll leave it then pump set to 1 then. Opened up to 2l/min. This looks like the maximum for this pump speed. Any higher and I'll need to go to speed 2. Yes just the 1 room running at the moment, and door is kept closed. Floor covering is indeed carpets (tog for carpet and underlay comes to 2), in the bedrooms and landing. Tiled in the bathroom.

Thanks for the repliy. Have got it currently set to 45° flow and 1.5 l/min. In the last 4hrs we’re still in the low 18’s. Would upping to pump speed 2 be a sensible option? At present although I’m not focusing on it, the delta T is circa 4-5°.

Hi @JohnMo, thanks for the reply. Would you suggest upping the flow rate to what it should be based on loop length or just going in 0.5 l/min increments? Insulation under the floor is 100mm PIR between the joists.

Just bringing this thread back up as we're now back to using the UFH and still struggle to get this 7° delta T. After much purging I'm confident now that all air is expelled. And following @Nickfromwales suggestion of opening up the manifold pump I did indeed find a tiny piece of metal. Wunda sent me out some manual actuators and have suggested to use these to achieve the correct delta T before sending me out new Salus ABA's. I'm going to set 1 loop at a time and the system was cold, as had been off for a few days, prior to restarting. The loop length I'm working on is 80m and flow rate should be 2 l/min, however I'm currently at 0.6 l/min and achieving delta T of 7°. Strange this is flow temp was set at 45°, and has been constant since I started this yesterday morning however now it's suddenly creeping up to 47°. Will see if that settles in the next hour or so. Temp of the room in question is gaining heat but extremely slowly, up from 14.5° to 18.5° since 1300hrs yesterday. Am I wrong in expecting the temp in the room to be up higher by now?

*Update* So pump has been silent since the 11th however I have noticed the flow rates have been between 0 and 1 (have checked with the loop lengths installed and 1 zone in particular should have a flow rate of 2 l/min). Spoke to Wunda about this and they are now suggesting trying out the standard actuators so have sent some out in the post (may arrive next week). I also spoke to Salus today who noted these actuators are very much fit and forget and have suggested upping the pump speed to 2 (was previously set at 1 due to only 4 ports on the manifold). Once I changed the speed back again came a whole host of noises (sounded much like air) and the green and red flashing light on the pump. One reasoning for this according to the Wilo manual is air in the system. So I entered the venting mode, its done its thing and back to being silent on speed 2. But I did notice some movement at the flow meters during this venting mode and in particular little movement from one of the meters as shown in the video below. The zone for that flow meter also has been the one with little to no flow through it, yet is also the largest of all the loops. Plan is now over the weekend at some point to get a hose pipe on it and see if there's any air in the whole system again. But whilst I'm doing work to the system am thinking probably best to open up the pump and check for debris as per @Nickfromwales suggestion. Can anyone confirm its just the 4 bolts on the front to be undone to view the impeller?

So situation first thing this morning with 1 zone calling for heat......silence! 🤯 Will get someone to monitor it during the course of the day, and then I'll do the same over the weekend. Assume if I remove the 4 bolts on the front of the housing that will give me access to the impeller to check for any debris lodged in there?

Thanks all for the replies. Got back home this evening, UFH is on and pump is back to being silent🤯🤯🤯 I'll check it again tomorrow morning to see if this may just be happening in the morning. Assume this either now means it's not a damaged pump, or the piece which was causing problems has been forced around a loop???

@SteamyTea the system was making this noise late last week/over the weekend. So on Monday the system was bled using a hose through the fill valve. No bits of pump came out during this process (I had the hose on the return go into the bath). Wunda have messaged back and said the green light at the top denotes the system is in air purge mode but I don't think that's correct. I believe that just tells you the pump is running. The air venting mode it has is indicated by a series of flashing light on the pump setting and pump speed lights.

@ProDave @PeterW thanks for your replies. Pump along with the whole system was first commissioned around Jan/Feb this year.

Up until a few days ago my UFH system has been working as intended and silent. Then suddenly I started to notice a lot of noise coming from it, sounds more like at the pump end. Spoke to Wunda and they expected this noise to be air related so I set about a couple of days ago and bled the system. A little bit of air came out, and upon restarting the pump and system is back to working, as far as I'm aware, correctly and silently. Then this morning it's back to being noisy, I've attached a video in case anyone can offer any suggestions. https://vimeo.com/769310848

I've got a Grabo and used it to aid lifting in glass and installing tiles. Would highly recommend.

@Temp No won't be rushing. Just keeping it as an option should the need arise. We've still got the downstairs UFH to go in at some point in the next couple of years so that may help in getting rid of the heat produced. Tbh at present I'll probably just leave the buffer set to turn off at 65°. We'll just monitor it to confirm all is working as it should.

@Temp @JohnMo thanks for that explanation. I think it's now solved but maybe smaller jets still needed, if there's a need to charge the buffer to 70°. I turned up the boiler stat to max (77°) and the buffer wouldn't get up to 70°, would get to 68-69°. Yet there was still 240v from the relay to the boiler. Thinking the controller still deemed it to be 'on' as it hadn't reached the satisfied temp on the controller. Reduced the off temp of the buffer to 65°, and relay to the boiler is now 0v. Think this is right now as the boiler stat was limiting the buffer max temp to be around 68-69°. And it is allowing temp to drop in the buffer. I left the house and flow was showing 69°, return 43° on the buffer. And the flow needs to see 40° before the boiler should fire again and charge the buffer. I shall see how it is tomorrow when I get to the house.

@ProDave ok, I'm now understanding the boiler stat. Still puzzled as to why when there's a call for heat and the buffer is under 45° it's still not firing up. And I've just checked the terminal 10 and there is 230v present. The controller solely monitors the temp via the 2 thermostat probes, the relay is what is connected to the switch live of at the boiler. Checked through all the settings and it literally is just what temp you want on and what temp to turn off. Nothing else to it.