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Grant 13kW Aerona3 - issues getting zones to temp

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MikeFl
(@mikefl)
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@crimson Hi. About 20 (30?) years ago it was important that the TRV was on the flow side of the rad, and there was an arrow on the TRV body to show which way flow should go through it; nowadays most all TRVs can be either side of the radiator, and it shouldn't matter (I still feel they ought to be on the flow, but that's just in my head). I have two radiators where the TRV is on the 'wrong' side and they don't suffer due to this.

 

I think it would be nice to get to the bottom of this 'clunking' - whether it's just normal expansion noise (maybe pipes too close together, or rubbing on a joist) or indicative of a foreign body trapped in the pipework or rad. However, with the higher flow rate on a HP, any debris ought to be whisked along and end up in your mag filter, unless it's really big. Is the clunking all the time, or just at the start of the heating period?

Grant Aerona 3 10kW


   
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(@crimson)
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Posted by: @mikefl

@crimson Hi. About 20 (30?) years ago it was important that the TRV was on the flow side of the rad, and there was an arrow on the TRV body to show which way flow should go through it; nowadays most all TRVs can be either side of the radiator, and it shouldn't matter (I still feel they ought to be on the flow, but that's just in my head). I have two radiators where the TRV is on the 'wrong' side and they don't suffer due to this.

 

I think it would be nice to get to the bottom of this 'clunking' - whether it's just normal expansion noise (maybe pipes too close together, or rubbing on a joist) or indicative of a foreign body trapped in the pipework or rad. However, with the higher flow rate on a HP, any debris ought to be whisked along and end up in your mag filter, unless it's really big. Is the clunking all the time, or just at the start of the heating period?

 

Thanks Mike, the clunking seems often (sorry describing a sound that I have no reference too is hard to pick a term, metallic knocking/banging/clunking etc), and not just the start of a heating period.  I'd say it happens every 45mins to 1 hour, but I think I'd need to properly note it down.  It's only on this radiator out of all of them in the house.  Appears to be TRV side - but will try and see if hear it again and locate which side.

I've been trying to look back at photos when I can of the project during building progress to see if in fact this radiator might be the last on the loop, but not 100% (ceilings were stripped back so joists revealed and new pipe work shown, but not 100% clear of the circuit of water flow as not everything is shown in all of them).

With work struggling to get the right moment of the ASHP coming on and seeing which rads heat in which order lol (nothing like watching something and it not doing it when you want).

 

…upon writing this after upping the UFR zone heatmiser 1C higher (can't wait for other half to moan it's too hot in there! but it's often not calling for heat that zone) to see if that would draw enough heat to get the ASHP going it commenced a cycle about 10 mins later, not 100% I got the very start but quite early on.  I'm not able to check the absolute peak due to meetings.  However it would seem:

 

LV2 1 and LV 1 2 seem to get higher temps sooner.  Then LV 1 2 and LV 2 2.  I don't have probes for the hall way radiator or W/C radiator, those arrive tomorrow.  However LV2 2 is always lower in temp than the other 3 living room rads by 1.5-2C.

 

Temps found:

Living 2:

LV2 1 (smallest rad): 32.8C / 31.4C - 1.4C diff

LV2 2 (largest rad): 27.6C / 29.7C - 2.1C diff

 

Living 1:

LV1 1 (middle sized rad): 31.1C / 25.8C - 5.3C diff - this seemed to always be around 5-6C different

LV1 2 (middle sized rad): 32.8C / 27.1C -  5.7C diff - same as above

 

It seems clear that Living 2 rads are taking less heat out.  I'd expect that with the smaller LV2 1 rad, but the largest of all living rooms LV2 2 - this seems to get lower temps in for a start and takes less heat out than smaller rads in Living 1.

 

Did notice temp in living 1 went from 18.7 - 19.1C in about 15 mins, so these seem to kick heat out when actually given temp, the cycles are just rather short.

 


   
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(@derek-m)
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@crimson

Try removing the TRV heads and check that the valve stems move freely, and by approximately the same amount of travel.

With regard to the noise, is it just like one clunk every so often, which could be due to the pipework contracting as it cools. When heating it may also clunk but more frequently.

This post was modified 3 months ago by Derek M

   
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(@crimson)
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Posted by: @derek-m

@crimson

Try removing the TRV heads and check that the valve stems move freely, and by approximately the same amount of travel.

With regard to the noise, is it just like one clunk every so often, which could be due to the pipework contracting as it cools. When heating it may also clunk but more frequently.

hi @derek-m , so completely confess very new to all this still. Removed the TRV head. In terms of the stem, how should that move? Up and down?

for a second on removing and replacing a few times to check things thought somehow did something good as temp started going up but must be a cycle just kicked in lol.

checked the pin in the head and that’s set for 10, was checking it wasn’t range restricted according to the manual for the Drayton TRV4

edit:

meant to say the TRV seems to work as dialing it down, atm when it gets down to 4 can hear the water flow noise stop

This post was modified 3 months ago by Crimson
This post was modified 3 months ago by Mars

   
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(@crimson)
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Somehow didn’t occur to me in all this. The utility room being UFR with its own heatmiser panel. Upping the temp on that panel invoked the UFR zone (valve lit up) out of the 3 zones in the plant room (those being up, UFR and down ) - so it shares this valve with the kitchen/diner which has its own panel - not sure how that works am sure someone can advise?

With that in mind thought I’d go with the heat dump idea of the heat specialist and up that slightly as it’s used mostly to hang washing in don’t think other half can be too bothered if it’s a bit on warm side. Heat dump being an attempt to get the ASHP to run longer cycles.

This post was modified 3 months ago by Crimson

   
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(@derek-m)
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@crimson

The valve stem should be up to open and down to close. For living areas it may be best to remove the actuator and leave the valve fully open.


   
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(@crimson)
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Posted by: @derek-m

@crimson

The valve stem should be up to open and down to close. For living areas it may be best to remove the actuator and leave the valve fully open.

 

Stem didn’t feel like I could push it down manually. Will try again

 


   
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(@derek-m)
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Posted by: @crimson

Posted by: @derek-m

@crimson

The valve stem should be up to open and down to close. For living areas it may be best to remove the actuator and leave the valve fully open.

 

Stem didn’t feel like I could push it down manually. Will try again

 

Try tapping the side of the valve and/or pulling the stem up.

 


   
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(@crimson)
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Posted by: @derek-m

Posted by: @crimson

Posted by: @derek-m

@crimson

The valve stem should be up to open and down to close. For living areas it may be best to remove the actuator and leave the valve fully open.

 

Stem didn’t feel like I could push it down manually. Will try again

 

Try tapping the side of the valve and/or pulling the stem up.

 

 

Thanks Derek will give that a go today.

 

I played with the TRVs a bit last night and temps seem to have changed, but going to confirm with more probes on the pipes incase placement across the pipe changes the reading.

Overall LV2 2 temp is still lower however than LV2 1 and LV1 1 rads. If no change with that stem I may look at adjusting the lock shield slightly on the higher temp ones to see if that brings this one's temp up slightly.

Living room 1 sitting at 19.3C this morning on a WC of max FT 45, min FT 30, max amb 20 and min amb -3.  6C outside currently (5C lowest overnight).  This is the warmer of the 2 but I'm short on probes so using as reference point.

I'm trying again to crush the WC to see if the room temp ever comes up, this should bump the flow temp up by 3C (max FT 47, min FT 35, amb settings same).  I think even at higher temps this just struggles with so much cycling off.

 


   
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(@derek-m)
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Posted by: @crimson

Posted by: @derek-m

Posted by: @crimson

Posted by: @derek-m

@crimson

The valve stem should be up to open and down to close. For living areas it may be best to remove the actuator and leave the valve fully open.

 

Stem didn’t feel like I could push it down manually. Will try again

 

Try tapping the side of the valve and/or pulling the stem up.

 

 

Thanks Derek will give that a go today.

 

I played with the TRVs a bit last night and temps seem to have changed, but going to confirm with more probes on the pipes incase placement across the pipe changes the reading.

Overall LV2 2 temp is still lower however than LV2 1 and LV1 1 rads. If no change with that stem I may look at adjusting the lock shield slightly on the higher temp ones to see if that brings this one's temp up slightly.

Living room 1 sitting at 19.3C this morning on a WC of max FT 45, min FT 30, max amb 20 and min amb -3.  6C outside currently (5C lowest overnight).  This is the warmer of the 2 but I'm short on probes so using as reference point.

I'm trying again to crush the WC to see if the room temp ever comes up, this should bump the flow temp up by 3C (max FT 47, min FT 35, amb settings same).  I think even at higher temps this just struggles with so much cycling off.

 

I would suggest that you start by reducing the frequency of cycling, by trying to balance the flow rate through the LLH. I suspect it will be necessary to ensure that all the zones are active at the same time otherwise balancing the flow rate will not be possible.

TRV's fully open and adjust room temperatures with the lockshield valves.

 


   
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(@crimson)
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Posted by: @derek-m

Posted by: @crimson

Posted by: @derek-m

Posted by: @crimson

Posted by: @derek-m

@crimson

The valve stem should be up to open and down to close. For living areas it may be best to remove the actuator and leave the valve fully open.

 

Stem didn’t feel like I could push it down manually. Will try again

 

Try tapping the side of the valve and/or pulling the stem up.

 

 

Thanks Derek will give that a go today.

 

I played with the TRVs a bit last night and temps seem to have changed, but going to confirm with more probes on the pipes incase placement across the pipe changes the reading.

Overall LV2 2 temp is still lower however than LV2 1 and LV1 1 rads. If no change with that stem I may look at adjusting the lock shield slightly on the higher temp ones to see if that brings this one's temp up slightly.

Living room 1 sitting at 19.3C this morning on a WC of max FT 45, min FT 30, max amb 20 and min amb -3.  6C outside currently (5C lowest overnight).  This is the warmer of the 2 but I'm short on probes so using as reference point.

I'm trying again to crush the WC to see if the room temp ever comes up, this should bump the flow temp up by 3C (max FT 47, min FT 35, amb settings same).  I think even at higher temps this just struggles with so much cycling off.

 

I would suggest that you start by reducing the frequency of cycling, by trying to balance the flow rate through the LLH. I suspect it will be necessary to ensure that all the zones are active at the same time otherwise balancing the flow rate will not be possible.

TRV's fully open and adjust room temperatures with the lockshield valves.

 

 

Thanks Derek, I'll mention this to plumbers if they come Thursday, I can only see one flow rate indicator in the plant room on the return (28l/s - heat specialist wanted to reduce that down, he got it from 36 to 28, but didn't want to go further as wasn't 100% on Grants spec for that).  Can't see any indicator from the ASHP which doesn't help matters.  I know the heat specialist tried to pro-long cycling with changing the ASHP speed (there's only 3 options) and the plant room pump speed (again 3 options).

Probes just arrived and I've placed them around the zone and rads.  With the squashed W/C, temps coming up slightly, but again cycling means it peaks very quickly.

Hall rad seems to show around 4-5C diff

W/C rad only 2C diff

Again the ones in Living 2 seem smallest diff (and coolest of the 2 living rooms by up to 1C v Living 1).

 

 

 


   
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(@heacol)
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@crimson Unfortunately unless you change the installation, anything you do will have little effect on the performance of the system. Heating systems are dynamic and change every minute of the day, Balance it now, with your system, and in 10 minuets it will be out again.

I am developing a Delta T controller which we will install on @admin 's system in a month or so. It will be commercially available shortly after that. This will help considerably improve the performance on units like yours as it will actively balance the flow rate to the demand, ensuring best performance.

Professional heat pump installer: Technical Director Ultimate Renewables Director at Heacol Ltd


   
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