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@ProDave apologies for not understanding this sooner. first off I apologies, I should have noted it's 70° the buffer is set to. I kept writing 75° as that's what it is on the boiler. If the buffer off temp stays at 70°, and the burner has stopped will the boiler still circulate water till the buffer stat is satisfied? Or does it all just come to a halt? Also what I'm failing to understand is why when there is a call for heat at the buffer is below 45°, the boiler was not firing? As for the 70° off temp, this is what was noted when I asked the query in a thread I started a while back. I assumed to allow a greater store of heated water for the UFH and to hopefully further reduce cycling of the boiler.

And just for reference last night before I left the house I turned off the UFH. This morning the temp in the buffer had dropped to 28° and 30°. When I turned the UFH back on to test terminal 10, the boiler did indeed fire up, but has not stayed on to satisfy the stat on the buffer. It has turned off and the buffer reads 40° and 41°. So does this confirm that the boiler is firing when there's a call for heat, but is turning off when the boiler stat is satisfied?

@ProDave Tested terminal 10 with the UFH off, reading is 0v. Turned on the UFH, there is a call for heat AND the buffer is below 45° and we have 240v. And yes there is a heat store within the boiler housing. But I don't believe it is firing due to that as the HW controls are off and hot water is not used in the house. I believe it will still maintain a set temp but this is dictated by the HW control knob on the boiler (which is set to 4 or 5. Still doesn't explain why the boiler is not firing when there is a call for heat AND the buffer is below the on temp of 45°. @dpmiller when the boiler was set to 75° and was firing every 45-60mins or so, it did keep the house heated well, during the night we lost 1-1.5°. One thing to note is that the buffer is set to turn off at 75° yet when the boiler was firing up (boiler control set to max), it never did reach 75°, stopping at around 68-69°. I now assume this is because the boiler stat is satisfied. And as the boiler turns on when the boiler stat is low I can't see how it's using the stats on the buffer to dictate when to turn on and then to switch off.

@dpmiller if I was to up the boiler control to 60° and see where that got me on at the buffer. but doesn't this then just eliminate the need for the buffer stats? And before when the boiler would cycle every 45mins or so (with it set at 75°), with the boiler stat at 50° at present, it took a good few hours for the temp in the buffer to come down to 45°. So to me that says much less cycling if I could use the buffer stats. @ProDave i'll get this done in the morning when I'm back at the house and report back. thanks.

@dpmiller is there anyway of getting round the boiler stat and relying on just the buffer stat's? @ProDave before I left the house this evening I did check the relay with a multimeter to see if it is indeed energising and can confirm it is, only when there is a call for heat. I did a test and turned the UFH off, and tested the relay and can confirm no power sent to the switch live of the boiler. There's 240v on the COM of the relay but I forgot to test the TDC. I hope this shows the relay is ok and is energising when it should, but I do need to test the TDC and the switch live at the boiler.

@dpmiller do you mean the boiler stat is what is being satisfied rather then the buffer stat's? @ProDave H/S = hubswitch. This is the Wunda hubswitch which allows connection of the smart controller and thermostats to the internet. TDC - temperature difference controller. This is the Grant temperature difference controller which monitors the 2 thermostats in the buffer. The thermostats both connect to this controller. B = boiler.

@ProDave The boiler was installed prior to us owning the house, however essentially the heating system is new. And strangely it was all working as expected during the testing phase of the UFH. Then it was all turned off and only turned back on again 3 or so weeks ago. I'm now only working at the house as and when on some weekends hence not ever noticing this issue earlier. Wiring I'm pretty sure is all correct as it's been fine before, just weirdly it's started acting up And for reference here is the schematics for the wiring,

@ProDave The temp in the buffer vessel according to the controller is 40° at the flow and return. The minimum temp set on the controller is 45°, so as there is a call for heat at the moment and the temp in the vessel is below 45°, the boiler should be firing. And yes, you are right that the boiler shouldn’t be firing all the time, yet during today there has been a call for heat all day and the UFH pump has been on. The temp in the vessel earlier was 63°, yet the boiler still fired, when it shouldn’t have as there was sufficient heated water in the vessel. This is when I noticed it and called up Worcester technical who suggested the boiler was probably firing up when ever the boiler stat was x amount of degrees below the temp set on the boiler. They suggested to lower the boiler temp to 50°, which I have done. And since then the boiler hasn’t fired and the UFH has used the heat stored in the vessel. But now the heat is lower then the ‘on’ temp set on the controller, there is a call for heat, but the boiler is not firing.

@ProDave thanks for the reply. The thing is, I’m currently at the house (not living here at the moment as got some other bits to sort first before moving back in), and there is a call for heat from the UFH. The controller is currently reading 39° and 41°. It’s set on that controller to turn on the boiler if below 45° and when there’s a call for heat. But the boiler isn’t firing. The boiler temp control is now on 50° as recommended by Worcester technical.

Got an external Worcester oil combi. A buffer vessel is connected to the flow and return from the boiler and this is used to supply heated water to the UFH manifold. The buffer temp is monitored by 2 thermostats which are connected to a Grant GSX1 controller, and an easy relay fires the boiler a) when there is a call for heat AND providing the temp in the buffer is below 45°. Today I noticed the boiler was firing every 45-60mins or so, and on the boiler control panel the heating temp was at max. A quick call to Worcester technical and it would appear the boiler stat is what is being satisfied rather then the stats on the buffer vessel. Anyone have any suggestions as to how to get the boiler to fir based on the stats in the buffer vessel?

@S2D2 as another option if you're thinking of replacing you could use a product like Supersoft insulation. It's made from recycled plastic. I replaced all my loft insulation with this stuff and it was a joy to install, no itchiness and easy to cut.

We've got the Ubiquiti AP's in the house and garden and was easy to install and provides full download speed all round the house and garden. Got a PoE switch which is in the AV cupboard in the garage which the BT router plugs into. Then the 3 AP's plug into this. Wasnt really much to set up, just customise not having the little light on. Literally plug and play. I'm sure there's more that can be done and when we move back in I'd like to set a dedicated guest access, but aside from that for home use I don't see what else is needed.

Got a freestanding bath from Charlotte Edwards and the waste/trap provided sits proud of the bath when it sits on the deck. One option is to cut out a section of the tile so the low profile trap can sit on that, however before I resort to that, just wondered if anyone has come across a waste/trap that's approx no longer then 95-100mm and has a overflow connection AND is of the click clack type? I did find a waste/trap by Geberit which is 89mm in height however it's for the turn type waste and unfortunately I have a slotted overflow so it can't be used. Oh, and if possible preference is for a white waste.

@dpmiller So set the pump speed to 2 on Saturday. Went passed the house and checked today and with one zone active the delta T is 2°. Is the 7° difference supposed to be when all zones are active or can if differ depending on how many zones are active. 2 of the rooms get a lot of solar gain during the day, so much they increase to around 24° according to the graphs on the Wunda app. Out of the 2 rooms at the back of the house, 1 is the bathroom which is where the manifold is located, the other is the main bedroom and the temp seems to hover within a degree of the set temp (19°). Is it worth dropping down to speed 1? Or maybe now set the flow rates as per if I was to use manual actuators, and then recalibrate the salus ones?

@dpmiller This is the pump and settings, set to speed 3??? Is this possible to slow down, I've not changed anything, it's all as it came from Wunda. @Adsibob Floor build up is 22mm T&G ply, underlay and carpet (underlay and carpet come to 2.1tog) in all areas upstairs except the bathroom which is, 18mm T&G ply, 6mm hardie, ditra, then tiles.

@JohnMo originally the flow rates were fully opened however I was then achieving a delta T of 0.5-1°. it's got slightly better since reducing the flow rates and recalibrating however today noticed we're back to between 1-2° delta T. @dpmiller do you think maybe manually setting the flow rates to what they should be based on the loop lengths whilst still using the salus actuators be worth a try? @SteamyTea Noted.

@jayc89 I'll give that a try. It did seem to help after I reduced it from fully open and recalibrated it. @JohnMo yes, I've got salus auto balancing actuators.

My first floor UFH system is now up and running and I'm struggling to get the 7° delta t between flow and return temps on the.manifold. Been speaking to Wunda to try and resolve this however the suggestions from thwm are getting better results but not quite there. When the system first went properly on I was getting a 1° (at best) difference. Wunda suggested manually turning the flow rate to 2.5, then recalibrating which has now achieved a 3°-4° difference. Manifold temp is 40°. They have suggested that this should now be fine, and to increase the manifold temp to 45° however I'm not sure how this will get me towards that 7° differential. I've had a read through many topics on here and have yet to come across a simile case and possible solution. Tomorrow I'll get some temps of the floor now I have my thermal camera back. Hoping I can get some suggestions from here as to what may be the cause.

Does it have a frost mode setting?

We used Origin for our aluminium windows. Set up a trade account with them and got access to the site to size and spec them up myself. The reps are pretty good if you need anything clarifying or queries with orders.

Could you not have a different heat source? Maybe gas or oil?

We have the Wunda smart connection box and hubswitch, and the control for the HW is from a connection in the hubswitch to the boiler. is it the smart stuff you have from them?

So a number of months have passed and the heating system all worked well during a short testing phase late last year. It's now on full time, as we're hopefully moving back in early Feb. Only issue was the temp probes being in the wrong connections on the Grant controller but a quick swap now has the buffer heated to 75º when there's a call for heat, and this doesn't happen unless the buffer is below 45º. Set this minimum temp in the grant controller as that's, at present, the flow temp at the manifold. More experimenting is needed, but at present with nothing on the first floor (awaiting carpets to be fitted this week) any lower then 45º flow temp and the air temp really struggles to come up to what has been set. It has even got cooler! Have purchased a thermal camera to check for any heat loss so will do more research with that. One thing I have noticed during these cold days/nights is that the boiler's frost protection kicks in as and when it needs to. As it heats up and circulates water, this does make its way to the buffer vessel and tops up the heat there (even when there's no call for heat from the UFH). Would this be considered a little perk so as not to waste any heat being generated, or is this a negative? Not sure why it would be a negative but I'm open to suggestions.

Has anyone used the above for monitoring thermostats?

@saveasteading Tiles are porcelain. Grout is epoxy grout. ok to use diluted bleach on it?