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PWM pump or not?

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(@bontwoody)
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1500 kWhs
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Ive just finished installed my new Samsung Gen 6 ASAP and have identified that I made an error. I ordered a Grundfos UPM3 AUTO pump thinking it had PWM, but even though it has the socket for the PWM lead it doesnt. At the moment i have it in radiator mode as a standard pump. My question is, shall I just leave it or get a PWM pump and sell the other on ebay? I will probably lose ยฃ50 in doing so but would it be worth it long term? A bit technical I know but I thought I would ask on the off chance someone has the knowledge ๐Ÿ™‚

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
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(@iancalderbank)
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I've used the grundfos UPMM 25-95 with the G6ย  which is PWM and its working as expected, flow rate is modulating with compressor rate and input power.ย  more info in this thread.ย as to what the gain is in efficiency I cannot tell you. my DT's are too small at the moment as I need to balance the rads so not an optimal system setup yet. I struggled a lot when researching the UPM3 variants as well, almost made the same mistake as you. then happened on the UPMM's at midsummer wholesale.ย 

if it was me I'd go for PWM....

ย 

This post was modified 8 months ago by Mars

My octopus signup link https://share.octopus.energy/ebony-deer-230
210m2 house, Samsung 16kw Gen6 ASHP Self installed: Single circulation loop , PWM modulating pump.
My public ASHP stats: https://heatpumpmonitor.org/system/view?id=45
11.9kWp of PV
41kWh of Battery storage (3x Powerwall 2)
2x BEVs


   
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(@bontwoody)
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Topic starter  

@iancalderbank LOL Hi again Ian. Im tempted to change it and need to make a decision before getting by Mixergy cylinder installed as it will be tight once its in. Glad Im not the only one who was confused, why on earth does it have the UPM socket??? I will have a read of the thread ๐Ÿ™‚

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
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(@iancalderbank)
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@bontwoody also don't forget flow rate. are you getting high enough with the UPM3?ย  in my case I'm a little low even with the UPMM-95 (getting 30L/min, target is 45L/min for the 16kw).ย  I've work to do on some of the radiator distribution pipework before I consider any changes to the pump side though, it's only been in a month.

don't fence your pump in. It is a component that can fail and need replacing.

My octopus signup link https://share.octopus.energy/ebony-deer-230
210m2 house, Samsung 16kw Gen6 ASHP Self installed: Single circulation loop , PWM modulating pump.
My public ASHP stats: https://heatpumpmonitor.org/system/view?id=45
11.9kWp of PV
41kWh of Battery storage (3x Powerwall 2)
2x BEVs


   
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(@bontwoody)
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Topic starter  

The flow rate is 15+ lpm on the highest setting, so fine for my 5kW heat pump, I could add and auto by-pass valve if needed but I have an extension coming and will need more rads (or UFH) soon. I dont really have an option with the positioning of the pump/cylinder but as Im only initially using an immersion to heat it, Im hoping the plumber can use long flexible hoses for the feed/output so i can roll it out if required (I might even put it on castors 🤣 )

IMG 9392

ย 

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
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(@iancalderbank)
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@bontwoody hmm I doubt they'll want to use flexi for a cylinder... anyway up to you.. to me its a risk fencing the pump in. are you sure there's nowhere else the pump can go? mine is 3m upstream of the ASHP just after it comes into the house, then another 5m to get to the airing cupboard, cylinder, diverter, etc... pump does not have to be colocated with those.

I wasn't suggesting bypass valves (I've removed mine that was there from gas boiler days - now have downstairs rads always on). More to check that you had enough flow rate and didn't need a bigger pump whilst you were potentially shopping.

I've often thought that one of the key non-trainable requirements for being a professional plumber is to be of a physiology where you have very slim and flexible but also very strong forearms and fingers...all those fiddly confined spaces to work in ๐Ÿ˜‰

My octopus signup link https://share.octopus.energy/ebony-deer-230
210m2 house, Samsung 16kw Gen6 ASHP Self installed: Single circulation loop , PWM modulating pump.
My public ASHP stats: https://heatpumpmonitor.org/system/view?id=45
11.9kWp of PV
41kWh of Battery storage (3x Powerwall 2)
2x BEVs


   
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(@bontwoody)
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1500 kWhs
Joined: 2 years ago
Posts: 218
Topic starter  

@iancalderbank Well, I have just had a trial fit and its tight but I think I could change it at a push. the pipework changes to 22mm in the cupboard so I couldnt really put it in the loft. The only other thought I have had is to raise the cylinder on a shelf but I would need to get the combi boiler out first to give me some headroom. At the moment the combi is supplying all the DHW so when it gets taken out the clock starts ticking ๐Ÿ™‚

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
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(@bontwoody)
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1500 kWhs
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Posts: 218
Topic starter  

@iancalderbank Da Dah, access to the pump 😆

IMG 9396

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
william1066 reacted
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(@iancalderbank)
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cylinder goes on the shelf and you crawl under to get at the plumbing? nice! 😀ย 

My octopus signup link https://share.octopus.energy/ebony-deer-230
210m2 house, Samsung 16kw Gen6 ASHP Self installed: Single circulation loop , PWM modulating pump.
My public ASHP stats: https://heatpumpmonitor.org/system/view?id=45
11.9kWp of PV
41kWh of Battery storage (3x Powerwall 2)
2x BEVs


   
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(@bontwoody)
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1500 kWhs
Joined: 2 years ago
Posts: 218
Topic starter  

@iancalderbank I cant actually take credit, it was a mates idea. Its actually quite roomy under there 😉

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
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(@derek-m)
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Posted by: @bontwoody

@iancalderbank Da Dah, access to the pumpย 

IMG 9396

I thought it was a seat, for when you are spending hours fine tuning your heating system. 😋ย 

ย 


   
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(@bontwoody)
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1500 kWhs
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Posts: 218
Topic starter  

Maybe a hammock might be better ....... 😆ย 

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
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(@derek-m)
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Posted by: @bontwoody

Maybe a hammock might be better ....... 😆ย 

I don't think that vertical hammocks work too well. 😎ย 

ย 


   
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(@william1066)
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Posts: 199
 

Posted by: @bontwoody

t was a mates idea

How heavy is the cylinder once filled? 😀ย 


   
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(@bontwoody)
Honorable Member
1500 kWhs
Joined: 2 years ago
Posts: 218
Topic starter  

Did I mention that im a dwarf ๐Ÿ™‚

BTW I contacted Graham on linkedin and mentioned the youtube error. He already knew ๐Ÿ™‚ย  He also reckoned that PWM on the Samsung doesnt work, so I think I will keep the pump I have!

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
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