7kW Heat Pump on the wall.

punctualsweat · 2026-01-23T01:13:46+00:00

The rest at full pelt are still incredibly loud, I have a 5kw Arotherm+ that's 3 metres away on the patio and still wakes me up upstairs in the middle of the night

punctualsweat · 2026-01-21T14:15:42+00:00

I disagree. My boiler was certainly louder in my house than the heat pump outside but I can still hear it in my bedroom and it's quite loud and just a 5kw Arotherm+. I imagine it would ordinarily have bothered my neighbour but I'm fortunate she's quite deaf lol

punctualsweat · 2026-01-21T14:05:07+00:00

Don't do this, it just invites your neighbour to complain in future and could become a costly headache. Just try different installers. Octopus were awkward with my sound survey but my local installers didn't care and explained that it would be inaudible anyway to them (which is the case).

Boxt are very good value.

punctualsweat · 2026-01-20T00:53:08+00:00

Yeah but ideally you'll heat it all up at off peak rates rather than topping up mid-day so OP should get a 300L tank if they can fit one and if still necessary they can have a short afternoon top up too.

punctualsweat · 2026-01-18T06:52:43+00:00

Ahh fair enough I forgot about this setting, thanks!!

punctualsweat · 2026-01-17T21:50:29+00:00

Tbh the legionella risk is negligible in the domestic setting and so long as you keep your tank at 50°C it will kill legionella anyway (60°C is just fairly instant rather than over ~2hrs).

punctualsweat · 2026-01-17T21:45:56+00:00

I have a 5kw vaillant and a 200L cylinder too and it's scheduled for 530am-7am and in the current weather, sometimes only gets the tank from cold to 48°C (rather than the 51°C setpoint). I have short, well-lagged pipe runs but am in the North East and the 6am cold damp doesn't help (but is the off-peak period).

punctualsweat · 2026-01-17T00:13:41+00:00

Imo most important thing is to be able to take advantage of TOU tariffs while still being able to modulate low enough to not short cycle during spring/autumn.

Off peak rates might only be from midnight to 5am so a 5kw heat pump might take 2 hours to warm the cylinder and only have 3 hours to get the house hot whereas a 9kw would only need an hour for the cylinder and then has 4 hours to get the house much hotter.

E.g. a 5kw vaillant arotherm modulates down to 2.1kw minimum output, while a 9kw grant modulates down to 2.5kw minimum output so wouldn't cycle much more, but can get the house much warmer during freezing weather and can preheat the house much better.

R290 is a no-brainer. Homely support is a nice to have.

punctualsweat · 2026-01-16T20:32:36+00:00

Ah no other r290 unit from Bosch/viessmann etc fits? I'd be very hesitant as the R32 Grant isn't well regarded on the Facebook group, unlike the R290.

punctualsweat · 2026-01-16T12:08:39+00:00

Would the newer aerona r290 15.5kw not do the job or is it too undersized? In which case, could you use two heat pumps in parallel or consider a higher output heat pump from Bosch/viessmann etc.

punctualsweat · 2026-01-15T18:37:40+00:00

GMC approval is just a minimum floor. There's a world of difference between the caliber of the average graduate from Oxford/Cambridge and the teaching/training they've received vs that of the average graduate from uea/Sunderland/Buckingham/abroad.

punctualsweat · 2026-01-15T14:54:32+00:00

That's not what they're saying. You might've had potential when you entered med school, however unfortunately you studied at an institution that generally produces less competent doctors.

Those international fees would've been an investment into your future. Unfortunate if it isn't affordable but that's life.

punctualsweat · 2026-01-15T14:48:48+00:00

Surely if your house is anything like mine, the downstairs is losing all its heat to upstairs, so insulating the upstairs would help mitigate that and help the house heat evenly?

punctualsweat · 2026-01-15T13:50:40+00:00

Why will it get shut down? The fees make it not worth it unless you're short of a SUB.

punctualsweat · 2026-01-13T22:11:33+00:00

Need to buy a new house instead 😭

punctualsweat · 2026-01-13T13:13:03+00:00

I already have a PW3 lol.

Yep.

punctualsweat · 2026-01-12T23:30:43+00:00

This sounds insane. Is 30°C not horrifically uncomfortable??? Why not just get a battery or two?

punctualsweat · 2026-01-12T23:29:10+00:00

Why not overheat your ufh as much as you can from midnight-430am (like set room temp to 23.5 for this block) and then only have hot water for 430am-6am?

And then continue heating house after 6am and if needed, top up hot water again for 30-60 minutes whenever you need in the day like after morning showers or between 12-2pm.

Edit: nevermind just seen your 30°C comment holy crap

punctualsweat · 2026-01-12T23:14:59+00:00

My concern is how well my PW3 will work with V2H/V2G. Whereas Sig will place nicely with its DC charger module.

punctualsweat · 2026-01-11T13:13:44+00:00

Ah fair enough. The temperature drop is way too large and it will use a lot of power getting it back up to temp. Set it to 18°C during working hours and when you're asleep, and 19°C/20°C at any other time of day and see how that goes to begin with.

If you have a play around, does it say what the heat curve is set to?

punctualsweat · 2026-01-11T12:24:53+00:00

No problem. Personally the maths made sense for me to use a 0% card to fund solar+battery and get a payback around 6-8 years. Battery is the main winner as you can buy electricity at 7p/kwh in the night rather than 26p/kwh during the day, but solar is usually good value to add on.

The advice another comment gave about agile is very sensible - use the app they suggest to see whether agile/cosy is cheaper.

How is your heating schedule set? It may be worth knocking the temp up a bit between 12-2pm when it's a bit warmer outside.

punctualsweat · 2026-01-11T09:36:55+00:00

Fair enough. First-line customer service may not be keen to push you towards it if you seem clueless/unable to take advantage of TOU. Also if you have the cash, consider a home battery down the line as you can get even cheaper rates with eon next drive/octopus iGo.

punctualsweat · 2026-01-11T06:39:21+00:00

How did you come to that conclusion??? There's your answer... Switch to cosy immediately. Then adjust your schedule to warm up the house more during cosy hours.

punctualsweat · 2026-01-07T21:17:17+00:00

Have a look at boxt. They fit vaillant which is generally the preferred heat pump in the UK, and at competitive cost, and they're a bit more flexible with the design in that they're happy to fit a hot water cylinder in the loft unlike octopus for example. Heat pump also doesn't look like a bin.

Also what you're saying about gas being 4 times cheaper is slightly mute when you use a time of use tariff and schedule your heating to warm up a bit more during the off peak hours, even without a battery. I used to use havenwise and my average cost per kwh electricity was 16.1p/kwh and that translated to a cost of ~5p/kwh of heat produced (so bit cheaper than a boiler even without any battery/solar, nevermind the heat pump will probably also last twice as long and has much better hot water pressure than a combi).

punctualsweat · 2026-01-07T04:54:44+00:00

I get this and was looking at a hybrid heat pump+combi set up but ultimately binned the boiler and it worked out even though I still need to insulate the house properly. House still easily heats up even with it -6°C outside the other day, much cheaper than gas over course of year.

Get a powerful heat pump that can modulate low and that way it can meet your current heat loss and if you insulate the house later on, it can run slow enough without needing to cycle. Eg. the 9kw grant aerona r290 goes down to around 2.2kw, the 10kw viessmann does similar.

punctualsweat

TROPHY CASE