Hey Toodles,

Is it just the hot water that's the blocker for these installers, or are there other issues? What do you think your peak heat loss is? It's possible that if it's just a few kW below that 15kW then you actually would need a larger ASHP to supply enough power at a given target temperature for radiators. For example, with a 55C flow, Samsung's 6th gen 16kW rated ASHP only actually puts out 12-13kW at cold temperatures, so this might be similar in your case.

@oswiu I had a survey carried out (an electrician and a plumber) that took them a very exhaustive 3 hours to complete during which I was told the heat loss was 6.5 kW, the EPC before solar PV was added is a ‘C’ with movement to be a ‘B’ once the solar was carried out. I intend to replace a few radiators that are marginal anyway and wish to improve the bathroom radiator to a heated towel rail style. The Sunamp unit require a LWT of 60-65 degrees and there will be an immersion heater element for any ‘top-up’ that might be required. I hope to be able to run the system at 35 degrees for heating and make the best of the SCOP. We have underfloor insulation (Q-Bot), cavity wall insulation, double glazing [one room is triple glazed] and 35+ cm of loft insulation and our property is semi detached. The companies themselves, well, I contacted approx 15 with my initial enquiry, many companies either did not respond, told me they didn’t serve this area or don’t have MCS certification. I have a survey being carried out next week with one company that should be able to ‘tick all the boxes’! I’m deliberately not naming any companies at this stage but the company who performed the 2 man survey were extremely good but, at present they are unable to carry out the type of installation I require - nothing sinister, it is just they are attempting to fit thousands of units nationwide and work to a fairly restricted regime and suggested that in due course as their engineers gain more experience and their training programme is

expanded, I might like to approach them again. This is fair enough in itself but my ageing gas boiler needs replacing and I WANT to have an ASHP fitted in the near future so have had to cast my net wider. There are many companies North, East, South and West of the area but few of them wish to travel this far.

Toodles

Sorry why do you need that brand? I am confused as to why. I see nothing in your existing setup which locks you in?!

Brand of what, the Sunamp? I am not aware of any other similarly featured heat batteries. I have limited space and a large tank is undesireable, whereas the Thermino unit are compact (yes heavy to get upstairs but no heavier when in use than 200 litres of stored water would be. I have’t mentioned the ASHP I have in mind as yet; I favour the Daikin range and will take the installer’s advice on model to be used.

Regardsd, Toodles

@toodles yes why do you need a sunamp? Seems like you are hamstringing yourself for no real reason? you say a tank is undesirable, but really what's the issue with a slimline tank?

Even a slimline tank requires space we don’t have; at present, we have a 99 litre HWT and even that has had to be shoe horned in the airing cupboard. We have no other space anywhere near the existing plumbing and other than a tank in the loft, the only place would be out in the garage with many many metres of pupework running throughout the house with major disruption to accomplish such an installation. Re-building the airing cupboard a further 10-15 cm. deeper is not an option!

@toodles

I have just been watching various videos from a company called Ecobubl, who supply both Daikin and Sunamp products. They have also had good reviews from forum members. Try contacting Julian on the forum.

I wasn’t mentioning companies that I had contacted but will now; Emilie at Ecobubl has been very helpful when I corresponded by email with her and I have also found their Youtube presentations very useful. Unfortunately, Ecobubl have sufficient work in the South West and are not able to assist as I’m outside their area.

Regards, Toodles

@toodles can't you just reuse that tank? Or get a heat pump compatible tank the same size? Frankly you'll save a fortune. Also I can't imagine a heat pump being useful in that scenario. Isn't the point of the sunamp that it holds an extremely high temperature? Whereas a heat pump you want to run as low as practically possible in terms of temperature?

The two just don't seem compatible to me, or maybe I am missing something?

The Sunamp Thermino unit stores the heat for mains water passing through it to supply hot water but not the space heating. The 99 litre tank is a slimline model but anything roughly equivalent for use with an ASHP will be larger due to the heat exchanger coil having to be larger. I have been offered ‘slimline’ tanks but they are all considerably larger and take up most of the height of the airing cupboard - result no space in the airing cupboard for airing things. In fact, time the hydrobox is also installed, a pile of pillowcases would be all that could be put in the remaining space. A sunamp unit releases a lot of space and is an elegant solution for such a small space. The heating cycle for the hot water can be run at night on cheap(er) rate electricity whether via the idling ASHP or using the immersion element; during the day solar panels may provide the energy to run the pump or the immersion element.

Regards, Toodles

@toodles have you tried contacting Sunamp directly to see if they can put you in touch with an installer?

Or maybe you could get a high temperature heat pump and keep your current tank. That new Samsung one in a different thread is said to be able to provide 70C even in extremely cold temperatures, then you could run it at cooler temps for heating. I know there are other high temp models as well eg Daikin has one and you said you liked Daikin models.