sharpener

We started with 7.1 kWh of battery and quickly added another module which I had allowed for so now have 10.65 kWh In an ideal world I would add a fourth module but that would mean moving the consumer unit so cba. Cosy suits us well bc the 1300 - 1600 cheap slot allows the HP to precharge the thermal store at the same time as the inverter charges the battery, all ready for the evening meal and keeping the CH going through the evening peak rate. With yr enormous slab @JohnMo you will probably do entirely without the HP during the peaks. I decided not to go for the Octopus Go etc EV tariff bc you need to play continual games to optimise the behaviour for the HP. Cosy is fit and forget. All I have to do is change the settings when I am away so the house can run from the battery during the allowable charging times, when the house is occupied this is not desirable as it cycles the batteries too deeply (simple explanation but not entirely correct).

Yes there was an intermittent feed that sprayed cold water into the air circuit. Brought the circulating air down to the temp of the cold water inlet but also ensured it was 100% saturated. Next to useless, worst machine I ever owned.

Ironically we discovered an acquifer only 1.2m down and right under our new rainwater tank location. So they had to bring in a dewatering pump - but the flat outlet hose kinks easily and I was up in the night sorting it out so the tank didn't float out of position before they backfilled the hole.

Even after the capital cost of having the borehole drilled and the treatment plant installed you need to factor in the recurring cost of replacement filters, UV lamps, chemicals and periodic water quality checks none of which you need with mains water.

For a friend they didn't remove the blanking plug in the connection to the sink waste so the machine threw an error code and didn't work. Can't see the point of paying £25 for someone to connect 2 pipes and plug the thing in. If there is anything out of the ordinary they won't do it anyway. IIRC hot and cold fill washing machines only draw from the hot on the high temperature programmes so you will not save anything on everyday washes.

Fit a solenoid valve then you can control it by a conventional time switch or over the internet by a Shelly plug.

Don't know about Panasonic specifically, but in general it would seem you pay a lot for the convenience of having these components packaged in a glossy white unit to sit alongside your kitchen cupboards like a boiler.

R290 is propane but the quantity is relatively small (960g) so even if it is inside the house (not clear from a quick read) the danger will be much less than an unlimited supply of natural gas. The compressor will be in the outdoor unit either way so not a problem.

Will make it worse. The cutaway view here shows the main active component is a standard plate HX, and from the description is it clear this is used to provide separation between the HP loop and a pre-existing heating system. Assuming there is the typical dT of 5 C between primary and secondary of the HX it means the HP will have to run 5C hotter for the same heat delivered to the home. It will not reduce the need for larger emitters in many instances, in fact it will make this more of a requirement to get reasonable CoPs. Their video is misleading about this. I don't see why they are targeting social housing in particular, or emphasise the saving on glycol. Anti-freeze valves are a readily available alternative. The remote controllable backup heater is novel but I can't see what form it takes. It does not seem to have a standard immersion heater boss, and if more than 3kW will need a new power supply to the airing cupboard. As it is designed to fit under the HW cylinder it would not appear to avoid the need for a new cyl. I would not have one.

Because the 12kW outdoor unit is more than 0.6 cu m we needed full PP. Our site backs on to a river in an AONB so visual impact is important. As well as the specified plans I included (i) a photograph of the house from the river demonstrating that the HP would be out of sight and also (ii) a photomontage showing that it could not easily be seen from the street either bc the level of the kitchen yard is about 5 ft below the surface of the road. The only objection was a technical one about my home-produced plans which was fixed by paying ~£20 for online ones. I would think so. Good luck!

Nothing about height, this is the full extent of the MIs on the subject: I suppose the accessibility guidance would be the same as a light switch but I do not have my IEE On-site Guide to hand. More important is to site it in a sensible room. Hallway is not always a good choice, it may be draughty or unrepresentative of the rooms you are actually trying to heat. There is an offset adjustment which may help circumvent this. If like me you are not using it to sense room temp and just rely on the WC then it may be more convenient to put it with all the other controls in the plant room. Often I have seen pix where it has been installed in the airing cupboard where it is neither use nor ornament.

The key point here is that the turn-down ratio of a heat pump is usually about 3:1. So the 6kW unit would happily run continuously at 2kW output. Hence on the face of it the 9kW would not be too bad, at 3kW. But if as @JamesPa says it is a 16kW unit derated by software then the min output is going to be over 5kW which is 2 1/2 times what you should have had. So it is going to spend most of its life cycling severly which is poor for efficiency and also poor for the compressor lifetime. I think you might usefully consider a Small Claims Court case for "not fit for purpose", the threat of this might miraculously cause a 6kW unit to be found!

Vaillant require only 200mm from the wall (250 if used for cooling). But their own ppl will not work off ladders so if you needed a repair under warranty you would have to arrange scaffolding or a tower. An approved installer might be different though. (I had a single-storey rear extension built and the main contractor had to provide scaff for the s/c brickies even though the brickwork is only 7ft high!). Sounds a situation best avoided.

Agreement between the gauge and the HP control panel depends on siting of the sensor wrt the internal pump in the outdoor unit. On the Vaillants the pressure sensor is on the suction side so what looks like adequate static pressure when off turns into not enough when pump is running. Not helped by my installers leaving the EV pressurised to the factory setting of 3 bar, which is too high for an HP and means it was not doing anything.

Not exactly. The black needle shows actual system water pressure, 1.25 bar might be a bit low depending on the instructions for your particular HP. The red needle is an aide memoire, you set it by hand to where the black needle is so you can see if the pressure falls subsequently. If this was set correctly then you have lost 0.25 bar since this was done. You may have a slow leak somewhere. You may need to top it up by opening the two black valves slightly until it is the black needle is correct.

Have had to do a similar job as a result of bodging by plumbers. Plywood is probably not a good material for this as half the grain runs in the wrong direction, you want all the grain running parallel to the joist so it will be maximally strong in bending. I put a sister joist of half the width on each side of it using long Timberlok screws. Bolting through would have been better but I could not get a drill in to make the clearance holes. The theory of bolted joints is that the bolts or screws pull the joint tightly together, then the shear loads are transferred by the friction between the faces (and not by the bolts). Consequently rough faces will improve the friction. I don't think adhesives are much help in this scenario though I did use Evostik Resin W - which has long been my favourite woodworking adhesive, I think it has a new name now.

As title, I looked on the Yale support web site, you would think there would be some info but nada. So I enquired via the comment facility but have not had a reply, and judging from previous useless experience don't reallly expect one. Hence I am assuming my HSA 3000(?) series alarm's central control box will require upgrading to something new with an internet connection. Can anyone tell me if their current offerings are backwards compatible with all the sensors in the house which use 433.92 MHz AM signalling, or am I going to have to change them all as well?

Have tried to follow the convoluted interaction of the SI, the explanatory memorandum and the original legislation but gave up. Can you say what you think it all means?

@JamesPa you will no doubt be dismayed by the following in the Explanatory Memorandum which apparently reinforces the MCS stranglehold on the business. And their potential competitors can legitimately complain that previous encouragement by HMG to develop alternative schemes has been a big waste of their time and effort. <5.16 Article 5 also removes “or equivalent standards” in order to provide clarity to installers that the MCS 020 a) – Air Source Heat Pump Sound Calculation (For Permitted Development Installations) is the relevant or applicable standard for heat pump installations. 5.17 Article 6 of this Order amends paragraph P of Part 14 (interpretation of Part 14) to make references to the updated MCS Planning Standards.>

Sorry, I have come late to this discussion but most of the points have already been covered by others. Yes @Jerry32, the information on compressor modulation was taken from my VWZ AI Appliance Interface module's Live Monitor screens, IIRC the field in question is helpfully called "compressor modulation". Minimum observed value is 27.2%. My system has been consistently averaging 2 starts per hour which I think is acceptable, anything less than 3 is generally reckoned to be OK, so cycling is not a problem. Now that heating demand is virtually over I am again grappling with the issue of whether it is worthwhile to use the HP for DHW, recent tests seem to have come out better than earlier trials though I have made no changes. What I really want to do is bypass the return path via the bottom part of the thermal store but unfortunately it does not have the necessary isolating valve so I will have to drain it and then refill with expensive inhibitor. Or muck about with pipe freezer. You will not have this problem! The 12kW graphs referred to above (the "Czech tables") start here on p51 https://www.facebook.com/groups/488794632317506/permalink/1093926388470991/ I don't understand at all the exchange you have had with Vaillant technical. I have dealt mostly with their Lyndon Stevens <Lyndon.Stevens@vaillant-group.com> who is pretty sound. If you know your annual gas usage Michael Podesta has a method of predicting HP size from this, you might have to adapt it slightly for LPG, he is easy to find on the web. Is this actually in force now? Although much-trailed, the last time I looked it was still in the works.

If you know what brand of HP you want I would start with their approved installers list as then you will have the benefit of any extended warranty terms. IME they may or may not do solar as well, depending on whether they are primarily plumbers or electricians. Am in the SW and had great difficulty in finding someone to (separately) fit a second PV array in 2022 and a Vaillant HP last year, must have contacted 20 firms before getting the installations done. Including many in Exeter but they may not want to cross the Blackdown Hills, there be dragons. Eventually I got the panels installed by a national firm who sent ppl from Humberside(!). The HP was put in by Eljay from Ivybridge, they were pretty good (and can do solar) but it might be too far for them. So you may have to be very persistent. Good luck!

IIRC there is a firm in NI on ebay which specialises in 2nd hand boilers. Shipment might be expensive. When we installed the HP there was a fully operational oil boiler which I advertised as suitable for spares (including on here) but in the end there were no takers and it went for scrap. However oil boilers are pretty robust and the spares for even 20+y/o models fairly generic and widely available. So unless there is some major failing like the main shell is rusted through they can be kept going more or less indefinitely.

Needed one capillary coupling bc there is no room for a compression one under the TMV, and took the opportuity to move the drain cock round a bit so I can now get a hose on it out through the cupboard door. Otherwise it is all easily dismantlable for access. A lucky bonus was that where the new T is there was a (redundant) isolating valve, and its end cap thread was the same so I didn't have to get the nut and olive off the pipe. Bizarrely the top joint on the T (which was all new) was the only one I had trouble getting to seal, all the re-used old olives sealed first time with a smear of Hawk White. As you say, happy days when it goes well but I am glad I did something else for a living.

Job hasn't turned out quite as I expected. Ordered a Reliance online, was sent old water-damaged stock with a date of manufacture 2010 so I asked for and got a full refund. Had noted the locking ring requires you to take the entire knob off so losing any relationship with the calibration markings (current model may of course be different). Also the bumf says all ends are compression but this is not true, the outlet is a union fitting that needs soldering to the pipe. Then ordered a 22mm Inta. More compact and seems better designed, though instructions are pretty sketchy. Regulates to 35C quite closely. Quite heavy and bulky bc (I think) the casting is the same as for the 28mm model, ports are just drilled smaller. Seems more flow resistance than the unknown old one, loop flow rates are about 1/2 what they were. Well 11 compression joints and 5 capillary ones later it is all in place with a few mm to spare and does not leak. But weather now too warm to evaluate properly. (Original pic is here, the scorch marks are not mine!) This softened the black magnetite(?) deposits sufficiently that I could carefully scrape the inside of the sight glasses clean using the threads of a 2 in woodscrew.

MCS position in the market is no less entrenched. They seem to have fixed many of the bugbears but the assessment position being in the middle of free space could still be problematic. Has there been discussion of this elsewhere on the forum which I missed? Can't easily find an authoritative link to an actual "in force" date, has one been announced?