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Grant 13kW Aerona3 - issues getting zones to temp

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(@derek-m)
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Posted by: @crimson

 

IMG 2256

Wasn't a criticism of anyone here by the way, was just me seeing if he had any insight. I think dumb luck that he spotted this.

 

Looks to be Sprzęgło hydrauliczne, took a photo but apologies can’t make out a model number.

Downstairs still sitting at 20.4c, so no champagne just yet. 

Is a concern the temp going out bottom right is now so high

IMG 2254

 

The bottom right temperature is probably high because the primary flowrate is now much higher than necessary. You could try dropping the pump speed.

If you don't achieve the desired room temperatures then you may need to adjust the Weather Compensation (WC) curve and/or balance the radiators.

I would monitor the system for 24 hours or more and let it settle down, then if necessary make only one adjustment at a time and wait for the system to balance before making any further adjustments.

 


   
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(@iancalderbank)
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Posted by: @crimson

Wasn't a criticism of anyone here by the way, was just me seeing if he had any insight. I think dumb luck that he spotted this.

Is a concern the temp going out bottom right is now so high

typical experience here is that LLH's are just a dumb box with 4 holes. I've seen documents about complex ones with internal baffles to direct flow, but never seen a picture of a system that has one. I guess you do!

the return temp is going up because there is now less heat going into the house than the HP is producing, so the return temp to the HP is going up. hopefully the HP will reduce its power, but I don't know how grant does that. Eventually the system will go through an off cycle. This is normal

you are now into the really hard bit, tuning and balancing a complicated system, so that the temperatures and the power levels balance and it runs "low and slow".

 

Are all zone valves are open?

Are all emitters in all zones getting warm? If some are and some aren't then the next step is balancing emitter resistances.

 

you found a 2 port bypass valve previously. Is it set to maximum? You don't want it to open. when plumber is next here, get him to fit an isolator valve next to it so you can fully close it. Or just cut and cap that length of pipe

 

With regard to the mag one, even though you have a working system now due to LLH right way round,  the fact the Mag One s there will mean that the circulating pump in the main unit will be working significantly harder than it would have to otherwise.  This will be a steady drain on electricity use, noticeable when the HP itself is running at lower power. System losses due to circulating pumps can be way more than people think. It is still worth having the Mag One replaced with a low resistance unit such as a Spirotech. you will then be able to drop the pump power down.

 

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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(@crimson)
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Topic starter  

Thanks all, will take this all onboard and feedback.

 

I’ve let the ASHP plumber know where we are, and mentioned the return temp v in. Will only do small tweaks every day or so. I’ve seen downstairs is creeping up albeit slowly now to 20.5c. Upstairs and downstairs pretty much in sync so suspect now at point of it having to heat up all zones. All zones are in demand at the moment. Probably overnight will be best way to tell where I am with this


   
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(@iancalderbank)
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Posted by: @crimson

Looks to be Sprzęgło hydrauliczne...

google translate polish to english: "hydraulic clutch" or "hydraulic coupling". a.k.a low loss header. That is the generic name for what it is, not the brand name 🙁

 

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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(@crimson)
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Topic starter  

lol, my bad, I even work in tech localisation for me not to check that shows not with it lately. Not a clue on brand tbh, I’ll see tomorrow if can find a name plate somewhere on it.  If not, will ask the plumbers what they’ve used. I do recall the plumber saying this is the one Grant recommended as their unit has built in immersion and too large for the space they had.

 

flow rate looks better, some more photos

IMG 2260
IMG 2261
IMG 2258
IMG 2259

 


   
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MikeFl
(@mikefl)
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Primary flow rate is good. Now it's time to sit back and stop thinking about deltaT, low loss headers, thermal mass, heating zones, ... have a break, let the system settle down, get well, and look again next week. It can become an obsession. Have a nice, warm, weekend. 

Grant Aerona 3 10kW


   
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(@crimson)
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Topic starter  

Thanks Mike, definitely going to rest up now knowing no need for a fire this weekend.

Thanks again all for help with this, some definite snags etc to resolve even if this is the heat issue resolved which I’d never have had a hope of knowing. Also the temp nodes were gold in making the issue extremely transparent (clocked plumber moving them around a lot to check things today).


   
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(@derek-m)
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Posted by: @crimson

Thanks Mike, definitely going to rest up now knowing no need for a fire this weekend.

Thanks again all for help with this, some definite snags etc to resolve even if this is the heat issue resolved which I’d never have had a hope of knowing. Also the temp nodes were gold in making the issue extremely transparent (clocked plumber moving them around a lot to check things today).

Having measuring equipment can be highly useful, though sometimes the results have to be interpreted carefully. Measuring the temperature of a pipe does not necessarily mean that sufficient energy is being transferred along that pipe.

Think of the old type 3 bar electric heater. Measuring the supply voltage does not indicate if any of the 3 bars are actually working, it is only by also measuring the current flow can the full picture be obtained.

 


   
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(@allyfish)
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  1. Great news @crimson on the primary flow. Get well soon in what hopefully is a warmer house. I need to research that LLH to see what internals could impact the flow so much. Credit to your plumbers for spotting this, even if it was their cock up in the first place!

   
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(@crimson)
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On the mend now thankfully. Things temp wise improved mostly but not quite up to what I’d expect. Downstairs never quite hits 21c without it basically ran 24/7. Had a lovely electricity usage this month, so that’s my worse case with a ASHP running way too hot and not coming in plus immersion use for hot water (but blimey not something I’d want to hit again). I’m seeing a temp drop of 1-2c from the top left of LLH to just before heating zones.

i suspect the grant ashp speed is running too high. Have a feeling plumber Friday left it on speed 3. Dropping second pump speed from 3 to 1 or 2 meant the temp just before zones was closer to top left of LLH. Grant did say if things running too fast emmiters wouldnt get as much heat output (that was before LLH and flow rate issues were spotted).

I’ll catch up with plumbers this week on next steps anyway but thankfully closer.

i have noticed up and under floor zones tend to hit temps more often. And noticed the ASHP quite a few times was off as outbound and in bound temps basically same so it’s simply not having to heat up as much. Just need that heat to come off more in the zones rather than blast round though (from my poor layman understanding).


   
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(@iancalderbank)
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@crimson radiator and ufh balancing is the key thing to look at here. If lots of flow is going to the upstairs and ufh, and less flow to the downstairs, that will be a reason why the downstairs doesn't warm up. Have your plumbers balanced the flows on the secondary side (I think I can guess the answer)?  The other would be are the emitters sized right but hopefully thats not it.

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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(@crimson)
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Thanks @iancalderbank , you've guessed right, they've not since come and done a full balance.

The room I work from was rather cold this morning, then realised absolutely zero heat from either rad.  Contacted plumber and he suggested maybe some air.  I spent literally 2 mins letting air out of one of them.  Waiting for it to warm up now (hot water cycle just finished so might be a while).

I'm praying sizing isn't an issue but I suspect it could be downstairs a problem with other issues that have happened here.


   
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