octopus heat pump deal / investment.

[ahas]

Hi, sorry been a bit quiet from me.

We had Octopus install our HP earlier this month. I did the maths and seemed like a good deal (to me).
11kw Daiken Altherma, 300l hot water tank, 11 new rads and I changed all my pipework to 32mm copper - some of my handy work / pipe bending below - I've never plumbed copper before in my life!

So far so good. Mrs is happy (winning already!) and says the house has never been warmer! It's not been Baltic but it's been around 2 - 9 degrees C up in the North East and the heat pump is coping well, I'm really impressed. Sub zeros will be the real test.
Its been pretty sunny also so means the HP been running off solar production during the day, battery when no sun and Octopus GO in the early hours. When there's no sun it just smashes my 7kwh of battery storage within a couple of hours.

I've yet to figure out my CoP, not sure how I do that with the Daiken.
Its running in pure weather comp which seems effective but I need to fettle with scheduling it a little to reduce kwh draw for DHW in the evening and space heating.

Any tried and tested settings welcomed which I can test.

Happy with the Octopus team and install. Wasn't without issues but the chaps did their best to make sure I was happy. Quality of work with my install team was exceptional.

You can just make out the water tank in the back.

Only negatives so far. Our showers are like a trickle of wee unfortunately, we've gone from 5bar combi pressure showers to 3bar hot water tank pressure.
Although house is wonderfully warm and toasty, rads are just luke warm which means towels dont dry like they used to on the rads. They're now subjected to wash cycle and dryer.

[nowty]

Looking good.

Have you got more battery storage on your shopping list for the winter ?, seeing as you have Octopus Go.

Surprised about your poor shower pressure, 3 Bar is what we have and the shower blasts through nicely.

[Mart]

Just a thought for the shower, but if you don't have one already, then it might be worth considering one of those showers heads that draw air through, and makes them feel more powerful. Usually they are to make the 'pressure' feel more, so you can dial down the water a bit. But it may help.

I think they start from about £5, but you may find deals on sites selling energy saving devices. I think I've seen them for as low as £2.

I know it's really cheeky, but I've also got an enquiry with Octupus, so would you be willing to disclose the approx cost? My online quote was at the start price of ~£3k (after £5k subsidy), but I don't expect it to be that low when 'they' find lots of problems.

[marshman]

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[ahas]

Looking good.

Have you got more battery storage on your shopping list for the winter ?, seeing as you have Octopus Go.

Surprised about your poor shower pressure, 3 Bar is what we have and the shower blasts through nicely.

I've been looking at a pylontech us5000c (I currently have 2x us3000c's) but funds don't allow it at the moment. Glad I went pylon tech, the ability to simply plug in another battery is perfect.

Yeah as per Mart and Marshman 3bar should be decent enough for a shower. I might need to look into it.

I know it's really cheeky, but I've also got an enquiry with Octupus, so would you be willing to disclose the approx cost? My online quote was at the start price of ~£3k (after £5k subsidy), but I don't expect it to be that low when 'they' find lots of problems.

Thanks for the shower tip.

RE costs, oddly my online quote came at ~£3k also! But it was determined I needed to change all but 3 rads in our house. Total cost £11.1k, less the BUS grant of £5k, means I pick up the remaining £6.1k (double my online quote then...)
Once agreed octopus lock the price. So a couple of weeks before my install Octopus decided I needed to change another rad to meet their heat loss calcs that was done at their costs.

I still think it's good value as a daiken altherma 11kw and 300l tank costs about £6k on its own!

The install team were saying in some earlier installs if there was any pipework that they found during install to be micro or grey hep2 they would switch it as part of the job. Acorrding to my installers some one got a full repipe to 15mm copper after it was identified underfloor was all grey hep2. Octopus picked up the bill.

But they're cracking down on that and the directive from head office is just to join on to existing pipework regardless of what lays beneath...!

What DHW system/hot water tank do you have? Gravity fed from a loft tank? "Megaflow" cylinder?

Ours is a conventional vented system with a cold water storage tank in the loft. We only have 1m head of water for one of the showers up stairs and it is "acceptable" - just. Must admit the main shower we use has a Stuart Turner shower pump, if you turn the shower on full you are "jetted" out of the bathroom and that is a 3.0 bar pump. Where does your 3bar figure come from or is it just a typo and you meant 0.3? Pressure is not everything, flow is just as important or possibly more so- a car hydraulic brake system runs around 60bar under normal braking, but the pipe is tiny and you wouldn't even get damp if you tried to use it for a shower. Our gravity fed shower with 1m head of water has a pressure of 0.1bar yet with 22mm pipe work it is OK - not as good as the pump fed shower but perfectly OK.

What size are the pipes feeding the shower? Are they still 15mm used when you had the combi? if so that will restrict the flow a little.

Cylinder is a 300l Daiken unvented thing. Like this https://www.plumbnation.co.uk/site/daik ... v8QAvD_BwE


Yep still same pipework before heat pump. We didn't touch the hot/cold water pipes.
Although I went to the effort to change all my heating pipework to 28mm copper. The hot / cold water pipe work remains on JG Speedfit, too much effort in a short space of time to have been doable.

[marshman]

One assumes the shower is all still effectively mains pressure so there really shouldn't be much difference, in-fact I would have thought the flow rate be better as you don't have a combi boiler modulating the flow to keep the temperature up (assuming your one did that). I would be tempted to do a flow rate test out of the hot taps and compare with a cold tap, they shouldn't be that different.

[Ken]

It would be better if people actually measured their flow rates - easy to do with a measuring jug and timer. One mans OK is another mans rubbish.

My gravity fed power shower is 8.5L/min which is fine for me. Without pump and therefore about 2m head gives c4L/min. HW tap in kitchen is 3L/min.

The biggest difference in all of this is the hole dia of the appliance as this is what provides the "jet" and i have experimented with different shower heads bearing in mind there are shower heads for low pressure systems and mains pressure systems.

I agree with Mart about the air injection as i have this on a Mira Sport instant shower (which i thoroughly recommend) and on this the air can be used or not and this is transformational.

[NikoV6]

14kW Ecodan here, £16K under the HIAS scheme.

8 all new rads and associated plumbing, 300l hot water tank and Honeyewell Evohome wifi TRVs on all rads

Weather compensation, 32degs at -3 for higher setting, 20degs at 15 for lower setting. 50degs flow rate

HIES pay us back over 7 years effectively £11,900 in quarterly repayments.

Man maths, got an ASHP (which is effectively too big but we have plans for extension which assessor was happy to include) for about the cost of expensive gas boiler

Wifi TRVs a bit of overkill but handy for zoning off rooms we dont need heat for

[Joeboy]

I've added our home to the waiting list for a heat pump quote through Octopus. They are estimating Summer 23 to be starting work in our area. Just realised that the gas boiler is now 20 years old!