Radiators with Daikin Monobloc - 9kW (EDLA09DA3V3)

rjmachin

I have a Daikin Monobloc - 9kW (EDLA09DA3V3) from Octopus with a mixture of new and old radiators.

With it getting colder at night, the heating is starting to kick out more heat (weather compensation).

However, while some radiators are getting warm to touch, others are still cold.

Some radiators have a warm pipe where the TRV (the nozzle with 1-5 on), but the pipe on the other side of the radiator is cold.   It looks like they are set to 5 or higher

I have a few questions if that's okay:

1. Should the outgoing pipe also be warm (I presume it is like a ring circuit - water goes in, then out to the next one?)?
2. If yes, could this be why some are cold?
3. To test this out temporarily and check each radiator, how can I put the heating on full blast?   Should I change it from weather compensation to fixed?   The installer did this on the first day it was running (and it got quite warm), but I am not sure how he did it

I occasionally hear a klunky sound in one radiator, like there is some metal or plastic inside, could there be a blockage?

Thanks

Robert

Exiled_Tyke

Uhm.  I'm no expert but it sounds to me like there's air in these radiators.  Have you tried bleeding them?   If it is as simple as this then job done.   It could also be that the TRV values are stuck which can often happen. If you take the tops off there is a pin in side which lowers and raises with the setting.  This may need a spray of silica or WD-40.  

Hopefully you don't need to run the system hot but if you do you need to enter the  installer code on the profile page to get to those settings. 

rjmachin

Exiled_Tyke said:

Uhm.  I'm no expert but it sounds to me like there's air in these radiators.  Have you tried bleeding them?   If it is as simple as this then job done.   It could also be that the TRV values are stuck which can often happen. If you take the tops off there is a pin in side which lowers and raises with the setting.  This may need a spray of silica or WD-40.  

Hopefully you don't need to run the system hot but if you do you need to enter the  installer code on the profile page to get to those settings. 

.
Thanks for your comment.   Yes, I have tried bleeding the radiators, the water starts leaking straight away with no air.

I will take a look at the TRV tops this weekend and check, thanks for the tip.

I have been to the installer menu, so no problem there.   Just to confirm, was I correct about putting it to fixed mode instead of weather compensation?

Reed_Richards

Heat pumps are usually set up so the outgoing pipe from a radiator is about 5 C lower in temperature than the incoming pipe.  I think that applies at the maximum water temperature and at lower temperatures the differential is less - but I have never been quite sure about that.

Exiled_Tyke

Yes Fixed mode allows you to set the flow temp.  Horribly inefficient though so don't forget to take it off again. 

saveallmymoney

You need to get a thermometer and balance the radiators. My experience is you can't tell anything by touch with the low flow temperatures of a heat pump.

matt_drummer

Exiled_Tyke said:

Yes Fixed mode allows you to set the flow temp.  Horribly inefficient though so don't forget to take it off again. 

Really?

https://emoncms.org/app/view?name=MyHeatpump&readkey=bbd1cd04728bd8c9f7acfb2ee51936d2

FreeBear

saveallmymoney said:

You need to get a thermometer and balance the radiators. My experience is you can't tell anything by touch with the low flow temperatures of a heat pump.

Better still, a pair of thermometer modules with sensors clipped to the pipes either end of the radiator. See this page for a couple of ideas - https://forums.moneysavingexpert.com/discussion/6558035/front-room-radiator-never-gets-hot/p2

Don't bother with one of those non-contact IR thermometers. Not accurate enough, and if the pipes are chrome plated, the readings will be off.

matelodave

how about one of these - takes both measurements and tells you the difference, although probably not ideal if you've got a very long radiator - https://www.amazon.co.uk/Temperature-Measurement-Monitoring-Electronic-Industrial/dp/B0DLNP98X9?dib=eyJ2IjoiMSJ9.aoR_dXQKpey05cyB1T1u8XMmAW_8dkOkm6r-GV-TeFyfT5MQ-9LfQSMYjRPjtYbyf-bi2v4ssFm5LH9p5FNQFxAdbFJGajSrCqCtEz166VfKD1aMSrr-RbpzsWaKJlo0faKswXdg5DrJP51zRSQwcD7ORaxojMEpGpICY0Ndi5C-wRTNPcS0Rgmg8Xleqe1JedAnEjhVkJHVoWCHoNUTJ7wzF4Eo_LLY15ppLvfkj4JhQUsU5yg8a1gcPtij4AXs4sjmnm5aUJ5wbro6smMM_vunqVYcz659726e54_2d3Q.7rGzbyYIncoMyra6kDZzSGb3WT1qMpdXk4iWevf9_fs&dib_tag=se&keywords=differential+thermometer&nsdOptOutParam=true&qid=1731072742&sr=8-117

If you try the method that @FreeBear suggest, makes sure that you check that the the two thermometer modules both read the same when clipped next to each other as they can be a bit random in their "calibration" Its what I use but then hold the sensors onto the pipe with a couple of inches of foam pipe insulation rather than clips to avoid external effects.

Reed_Richards

matt_drummer said:

Exiled_Tyke said:

Yes Fixed mode allows you to set the flow temp.  Horribly inefficient though so don't forget to take it off again. 

Really?

https://emoncms.org/app/view?name=MyHeatpump&readkey=bbd1cd04728bd8c9f7acfb2ee51936d2

@matt_drummer, you're the exception that proves the rule.  How many others operate in Fixed Mode at such a low temperature as you use?

matt_drummer

Reed_Richards said:

matt_drummer said:

Exiled_Tyke said:

Yes Fixed mode allows you to set the flow temp.  Horribly inefficient though so don't forget to take it off again. 

Really?

https://emoncms.org/app/view?name=MyHeatpump&readkey=bbd1cd04728bd8c9f7acfb2ee51936d2

@matt_drummer, you're the exception that proves the rule.  How many others operate in Fixed Mode at such a low temperature as you use?

I used to run my 9kW Daikin at a fixed lwt of 42c before my radiator changes and about 34c after.

I always aimed to keep the electricity consumption at the absolute minimum. Lower flow temperatures resulted in the same or greater electricity consumption and less heat.

It was how that heat pump was most efficient. I went through every possible way of running that heat pump and I got the best efficiency of anybody with that particular heat pump. I spent hundreds of hours trying everything and watching the results.

The monitoring makes it possible to find settings that give the best efficiency and those settings with these Daikin heat pumps is not what logic tells us it should be.