JohnMo

Had a look at mine, and pump doesn't shutdown, it may slow down but doesn't stop. As the paddle moves it doesn't cut flow off, flow basically transitions from one port to the other, with both ports open until the DHW port closed. Assuming the UFH manifold is fully open it shouldn't see an issue. Do you have the piping all clamped up as it should be? No air in the system? If it's water hammer, the pressure wave need something to hit, and bounce back. A photo of the valve and the piping to UFH may help. Assume you don't get any fault codes?

I would look how this is reflected in room layout, some rooms may only need straightening out with self levelling compound, others may need way more, it also depends on the area of the floor how much needs to be corrected. We did all the correction that was needed a short time before floor covering went on.

How are you controlling the 3 port valve and pump - is all via the heat pump controller or something else? What valve are you using?

Did you finish this after topping up system pressure?

Woke this morning, after thinking I had a stable system, with flow temps bouncing about. The bouncing occur soon after a temp drop overnight. System currently looks like 4kW heat pump at min modulation 1kW, UFH with single fan coils (60L), volumiser (50L). UFH is within 100mm slab. Previously 6kW heat pump and at min modulation 4kW, the rest the same as above. For my previous heat pump volume was king to cycle control. Current setup not sure the volume adds anything positive, it adds to system inertia and leads to slow feedback to heat pump. Think the control system is looking for a more timely feedback to changes to running parameters. The thick screed, big water volume (via the volumiser) adding too much delay to changes, such as return temp staying stable for too long after a controller input, so control throws out a further command, feedback comes back (late), so the controller keeps over compensating. We get a yo-yo as witnessed. Luckily the volumiser is easy to bypass, so this was done earlier. Within 5 mins of the change, the flow/return and power input became very stable. Looking at yesterday and todays day time temps they are almost the same, but CoP has jumped from 5.2 to 5.4 during steady running. Will see overnight as temps swing about outside, if this has calmed the down.

Then once all working again, inhibit system with heating system inhibitor and biocide (same brand and type as previously used). Or if you have glycol, add glycol to the correct ratio.

As a country we seem to do A or B, it all too binary. Heat pump or gas, best bang maybe hybrid for a lot of the existing housing stock, 90% of the time running a heat pump, almost zero plumbing changes. Oil & gas, yes or no, we close refineries, export what we produce, then buy it all back at inflated prices. We just import a pretend net zero from somewhere else. The politicians all need a good sacking and be replaced by people with common sense.

Utter nonsense, currently working part time on a new field 20+ years design life, financially its a go, politically it may be stopped. Plenty of other proven reserves, but stopped mostly for political reasons. Same in the north sea. This will the third project I have worked on in the last couple of years, good production rates, all the others stopped due to politics. Existing field development has stalled also due to politics. Anyway most of the oil produced in the UK is mostly sold abroad. UK Production 31 million tonnes Imports 42 million tonnes Exports 25.4 million tonnes - we can't refine it Consumption ~60-70 million tonnes

It shouldn't rise too much, if it does that's an issue. Your system will have an expansion vessel this has a rubber bladder in it to absorb the extra water volume. Extra pressure doesn't aid anything, 1 bar is fine. You pressurise to help remove air from the system, any air vents or bottle traps should be opened to release any air a week or so after the start of the system, then closed again.

Turn off the isolation switch outside by heat pump. Leave it off for a couple of seconds and switch back on. Or if the controller is on its own power supply, switch that off and on again. Doing both will not hurt anything. Makes sense, immersion are generally 3kW so that plus any other loads in the house.

Flick on the immersion for hot water. Looking at the state of the filter/strainer, your system is full of crap. If you have zero pressure in system it will not bleed. But top-up water to get around 1 bar on the gauge you show. Then switch off power to heat pump, this maybe needed to reset the error code. Switch on and see if cleared. If so it should start up. If pressure has dropped again tomorrow you may either have a leak or you heat system expansion vessel has failed.

Milliwatts per km? That will be lots and lots. Think you mean MW per km

Looks like premium brand markings on any old pipe. Just get Pert-Al-Pert 16mm pipe. I got everything from Outsourced Energy. They do Ivor stuff which is good and good service. You only need pipe, manifold and 16mm euro cones, and staples. https://www.outsourcedenergy.co.uk/product-category/pipe/aluminium-core/ My £2100 Haier heat pump is working great, 4 degs outside CoP of 5.1. £500 for direct unvented cylinder

Way bigger per kW. Velocity through heat exchanger certainly seems a lot lower.

We are the same - but no AC. We are NE Scotland and no one needs Aircon in Scotland do they? Our UFH cooling went on mid May and was switched off in Mid September last year. Not as effective as AC, but makes life bearable. Without cooling in the first year, we got lounge temps in the late 20s any day the sun came out - don't matter if it was cold or hot outside. As soon as we had building sign-off, I installed a heat pump purely for cooling the floor.

That's a killer, motivation once in the house is hard to come by. Our roof was going on this time 5 years ago (where has the time gone), but was on mission, motivation was easy, I didn't plan or expect the build to take more than a year, which it didn't - year two would have been much harder. Lists helped me - a list of 10 achievable things, strike them off at the end of each day, anything left add to the next days list - even if you are not doing them and you are paying someone else, you see progress. Progress is a motivator on its own

Just went back and looked for a similar period of running for the Maxa heat pump, similar outside temperature, CoP here is 0.86 lower, doing the same heating. Flow temp was up to 30 degs to compensate for cycling. Haier is flowing between 25 and 26.

I have now been running for a couple of days, and have now got it running in a stable manner. Out the box settings are fixed speed pump and 100% speed setting. There is also a selection to be dT controlled and variable speed circulation pump. If you set to dT control the default being dT of 5 degs. Initial run was on a setting dT of 4 and variable speed. Problem I found was floor return temp was a very stable 23 degs and I had a target of 26 flow temp. So the controller was trying to get return temp to drop while maintaining a target flow of 26. A bit of a mess, plenty of overshoot, then undershoot outside was between 5 and 3 in the 4 hours window, CoP 4.17, ok but not great. Tried fixed pump speed similar results. This morning house was warmer than I wanted, so lowered WC curve and set to dT control and lowered dT setting to 3. Last 6 hours of running - 3 hours spent bring floor temp down a degree, think the spike maybe the energy integral adding energy to floor to catch up. When you zoom in, it's very controlled and deliberate. Then 3 hours running steady state and a CoP 4.96 over the 6 hours. Actually outside temp over the 6 hrs was between 2 and 4 degs. Defrosts, seems very resistant to freezing, only one defrost cycle so far. Took 4 mins and used 0.27kWh of thermal energy.

Think we are well capable, but politics gets in the way - one party does the speak and sells the idea, puts funds in place for after the next election, they get booted out, the next lot comes along and says that's a shite idea, have some austerity instead, we're (the nation) is skint. Repeat...

Basically to Peterhead (NE Scotland), then via a subsea high voltage DC cable to pop out the sea, somewhere beneath Drax power station. Assume there will be an AC to DC converter station at Peterhead and a DC to AC near Drax.

You have a slight issue, with the compressor stations that boost pressure along the route. You have to have ab electric cable diverter around the compressor stations and exit and entry points for the cable. Not sure it's easy to manage that plus the safety risk of liars of pressurised gas, high voltage electric and entry and exit points for oxygen to enter the system - sounds like a massive UK wide bomb waiting to happen.

My view and experience with MVHR is don't expect any cooling from it. Chilling slab is an all day affair - low and slow wins the day. Maybe better, once house is warmer than outside open all the windows, when outside is warmer than inside do the opposite. Keep floor temp cooler than 20 all the time, boost floor cooling if room get over 23. Leave the MVHR to do it thing, no place for home assistant, just set it up at commissioning and leave to run.

Photo showing rear of unit and piping, lagged with primary pro insulation. 2 x antifreeze valves (warranty requirement) and 2x isolation valves, then flex hoses and then 28mm pipe. Final wiring scheme Seasonal switching between heat and cool. Reused light switch, hardwired to UFH controller and ASHP wiring centre, located by UFH controller. Single zone with jumper across zone terminals, so always on. Secondary set point, wired from UFH controller via an EPH TR1-TR2 Two Way Wireless Switch. A call for heat or cool selects Smart Grid SG terminals, and give a demand for 2 degree uplift in heating or a reduced flow temp of 2 degrees in cooling. (Manual had wrong wiring diagram for this, wiring terminals and functions didn't match, so trial and error approach taken). This function uses the humidity sensors within the UFH controller to give a cooling safety shut off. It allows background cooling setting (19 degs flow temp) and then when house increases in temp it steps to 17 Deg flow temp. In heating mode, summer house stabilises at 18 degs with normal WC settings, so boost is used to increase to 21 when we use it. Communication cable to outdoor unit. Pretty simple wiring overall. If I didn't do cooling there would be no additional wires, just a Comms cable. DHW is still being done by immersion. Overall heat pump just seems to run, no on off cycling.

I had a flow meter error over night, so it stopped the heat pump, but interestingly the circulation pump continued to run on off every 15 mins. Checked the strainer all clean, reset the controller and it all restarted fine. Maybe some air still kicking about. Checked the control status log and it shows actually flow rate against an internal estimate of flow rate when it thinks it should be doing 20L/min it's actually doing 19L/min. Which also aligns well with the heat meter. So don't think there is an issue with the flow meter. Heat pump now playing catch-up and running flat out flow rate up to just under 20L/min.