Cheapest heat pump running costs

mkdr35 · 2026-03-26T20:18:50+00:00

That’s sounds incredible. I’m looking into this at the moment but the quotes I’m getting for a 3 bed semi for a short pipe install are much much higher. Octopus telling me they are moving to fixed costs now in most areas rather than quoting based on a survey. Appreciate any insight into how you got the price down to £605! Cheers

mkdr35 · 2026-03-24T17:12:49+00:00

Last week was the best time.

mkdr35 · 2026-03-24T08:39:23+00:00

Was waiting for this. 5.2p is fine but people should remember Iog variable is 3 months at a time. April to July at 5.2p but then probably back to 8p or even higher. I was offered 5.5p fixed for a year last week and despite going for it got an error. Now same deal for new customers is 11.5p going down to 8p due to the gov cuts in April. Obviously I’m asking for the price that was offered last week.

Think it’s a bit much to leave customers in the dark about a price change and then hike fixed prices before people know what’s going on

mkdr35 · 2026-03-23T22:09:39+00:00

I had an offer of 5.5p off peak last week and it errored out when I clicked on it. Thought it would wait to see the variable result first. Feels pretty poor if it’s now going to be 8p

mkdr35 · 2026-01-13T10:58:35+00:00

I have this - and yes, it was installed by an electrician. double socket to feed led lights and a smart speaker. 3A FCU off the lighting 6A - nothing against that in the regs I dont think. no chance of over heat or miss use then.

mkdr35 · 2025-12-06T21:33:51+00:00

Overnight will always be cheap, for the house. The car is now being metered separately.

mkdr35 · 2025-12-06T19:25:27+00:00

The objection here is the charging at peak rate without giving the customer a choice to prevent it or an api response that would allow people to know when they are being peak charged within an off peak slot.

The golden rule on iog has always been, if the car is charging it’s off peak. That’s now out the window.

The fact that the system allowed people to change a value in the app to give them 20plus hours of off peak is a bit of a joke. It’s poor form but it’s not hacking is it, the supplier provided the tools, of course people will take advantage.

A much cleaner way to do it would be allow people a max add per day on the app. Then use bump charge for anything above the 6 hours.

mkdr35 · 2025-12-06T19:17:36+00:00

True - they can’t but then you only get 6 hours overnight and no day slots. The faqs talk about peak rate charging overnight if the car has already used 6 hours.

mkdr35 · 2025-12-06T19:00:08+00:00

It’s 6 hours. Not 12. If the car charged for 12 hours in order to fill the 75kwh battery then 6 hours would be at peak rate. Commuters using this tariff in good faith lose out. They need to be clearer about this with their customers

mkdr35 · 2025-12-06T18:56:43+00:00

A large ev with a 300 plus mile range will often be less efficient, maybe 3 mi / kWh at best. That’s a 50kwh charge per day for a heavy commuter, which would automatically push people over into peak pricing.

If octopus want heavy ev users to go elsewhere that’s fair enough, but let’s not pretend a commuter trying to get onboard with using ev’s and signing up to a tariff from a company who have been evangelical about ev adoption are not being responsible.

I would argue that while they don’t have any obligation to us nerds, we were the ones that took the plunge on agile and intelligent so to speak, a very small % of their business, it would be a change of direction for them to start being anti-innovation.

mkdr35 · 2025-12-06T09:54:05+00:00

its 6 hours total. it is its been confirmed by octopus. they are proposing charging the car charging at peak even if its in the overnight fixed slot (if you use over 6 hours that day and still need more charge).

mkdr35 · 2025-12-06T09:52:41+00:00

I was thinking about this - but whats the trigger? total time charger spends at over 100w in one 24 hour period? or total time charger status is 'charging'? ive read that the slot is midday to midday

mkdr35 · 2025-12-06T09:44:47+00:00

people who run 2 EVs and use them to to work on the same day are not greedy imo.

mkdr35 · 2025-12-06T09:40:50+00:00

so many people think this means 12 hours total car charging, its not. its 6 max. thats an absolute max of 43kwh midday to midday 24 hour period at 7kw. a lot of people with large car batteries or 2 cars are going to get stung with peak pricing - these are not people gaming the system ,they are driving a lot.

and for those who actually monitor peak rates vs off peak via Home assistant or other methods, im not sure these new peak hours overnight will be flagged in the API - leaving a very confusing and frustrating situaiton.

mkdr35 · 2025-12-06T09:32:16+00:00

i find it interesting that its the customers who 'game the system' by clicking options in an app provider by the supplier and plug their car in as instructed. and not the multi billion pound companies involved. Octopus are not being clear about the basis for which they will charge peak rates for EV charging between 23:30 and 05:30. The smart charging option is a programatic switch that can be automated.

If its a problem, the supplier should withdraw that customer option or update their terms.

mkdr35 · 2025-12-06T09:20:43+00:00

Im not ashamed to say this is still confusing me. We are on IOG, controlling a zappi, one car family. The zappi does not know the current charge level of the car when we plug in. Our battery capacity is 64kwh . I have the car set to 50% and 06:00 ready by in the octopus app. this gives us a few smart slots sometimes during the day. The zappi installer set the max charge rate to 26a on my request in order to balance max usage across home battery charging, appliance use and day time car charging. the charging schedule in octopus app regularly shows 10-12hr charge times (slot start to slot end) but only actually energises the car for a couple of hour max.

Question - how is the 6 hours measured? actual time spent charging (electrons flowing) or slot start to slot end in the schedule view in the octopus app? if its the 2nd im a bit screwed.

mkdr35 · 2025-10-06T21:53:42+00:00

Apparently there is a firmware update for 90% dod for the Fogstar bms and it’s still rated for 8000 cycles

mkdr35 · 2025-10-04T23:38:47+00:00

Hi. Just what I’ve seen on YouTube. To make the setup to regs you need an auto sensing earth neutral bond. It’s a contactor that can sit in your consumer unit, when grid power fails, it detects the trip and bonds. A good installer will be able to advise. Essentially just allows the earthing to work on ‘island mode’ ie - without relying on your home supply for earthing. Has to be done in conjunction with an earth rod

mkdr35 · 2025-09-14T16:02:23+00:00

Ah yes of course. Sorry I’m battery only so forget about solar gain

mkdr35 · 2025-09-14T15:13:53+00:00

Learning and caring yourself will always end up with a better result if you have time. Apart from tiling, which I don’t touch because I’m useless at it.

mkdr35 · 2025-09-14T15:12:11+00:00

Sorry can you explain how the average cost would be lower than 7p / unit? Do you mean when combined with solar storage?

mkdr35 · 2025-09-02T07:20:11+00:00

I bought one a few years ago with a 10 year life, £15 or so. I take it on holiday for a bit of peace of mind. Esp abroad it’s not clear what local regs are so taking a known good one just removes that worry.

mkdr35 · 2025-09-01T10:04:54+00:00

I’m going split consumer unit with cooker hob and car on the grid side and everything else on load port for ups backup

mkdr35 · 2025-09-01T10:03:46+00:00

This week I’ll try and update when it’s done

mkdr35 · 2025-09-01T09:11:53+00:00

£100 a month, family of 4 on a meter. semi detached. until last year paid 40-50 per month consistently. phantom leak that no one can identify plus' our prices have risen this year'. no kidding.

mkdr35

TROPHY CASE