@bontwoody 

I think they don't like being just a pump distie and want to keep stock to sell with a heat pump as a package. They've been good with the customer service to me - due to a packing error they sent me the wrong pump, when I told them, and said needed a bit that I forgot so they did a free next-day courier for the pump swap and the extra bit.

but I bought mine from them with the heat pump, hence why I got it. I didn't find the UPMM anywhere else. which is peculiar.

which pump were you trying to get from MSW?  UPMM or something else? I have a whole list of suppliers I searched my way through before so let me know.

I Found this one https://theunderfloorheatingsite.co.uk/shop/water-under-floor-heating/pumps-packs/underfloor-heating-pump-grundfos-upm3-flex-as/

Its listed as having a PWM A Profile not C, does anyone know which profile would be correct for the Samsung Gen 6 HP?

It was this one I ordered, but at the time it didnt have the comment about being sold with a HP

https://midsummerwholesale.co.uk/buy/renewable-heat-accessories/grundfos-upm3

A is what you want for heating. C is for solar. the FLEX AS is available on a number of sites. just make sure you get that one not the AUTO you already have!

a tad cheaper

https://www.handyheat.co.uk/product-page/grundfos-upm3-flex-as

Thats quite a bit cheaper, thanks Ian. On par with the Midsummer price for the lower spec pump 😀 once you factor in vat and delivery

double double check it is the right version - as the pic is for an AUTO - and includes the PWM cable . Have seen it sold without (even though its a PWM pump). as a spare part they are daft price (only seen one supplier, 20 quid or something). this is all the pain I was having before I found the bundle from MSW (which meant buy the heat pump too, but that was fine!).

LOL, great minds..... I just sent them an email having noted the image was wrong. Ive got the cable, stoves and solar were pretty good £8 I think although I was trying to find a 2m cable which you can get in Germany.

Posted by: @bontwoody

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Bad news Im afraid, Midsummer Wholesale took my order and confiirmed it and then the day after cancelled it saying they are now only supplying the water pump with a heat pump! It didnt say that when I ordered it (other pumps did). Very poor customer service IMO, they should have honoured the deal that was made. I wont be using them again, but finding another supplier is proving difficult.

So will you get a free heat pump? 😋 

In which case you will have a spare water pump and heat pump. 😎 

@derek-m LOL. I dont have room so had to say no to both 🙂

BTW, here's the effect of PWM. I think we're right at the min output of the ASHP once this reaches steady state at around 14.45. without PWM I suspect it'd be less well behaved.

@iancalderbank Very well behaved Ian 😊 thanks. No reply yet from the pump seller 😞

@iancalderbank

Whilst the graphs appear to be excellent, they are rather difficult to read. Could they be posted separately?