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Urgent Glycol Question

Air Source Heat Pumps (ASHPs)

Last Post by IRMartini 1 year ago

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Lokisam

(@lokisam)

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Joined: 2 years ago

Posts: 29

Topic starter 19/11/2024 10:16 am

There's no glycol in my heat pump system at the moment. The installers were going to add it after I'd finished decorating. Everything took ages and we ended up in a wrangle. Last night I remembered its still in two containers under the stairs. I kept the pump running on and off overnight last night as a precaution. Is that necessary? Do I need to worry?

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Toodles

(@toodles)

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Joined: 3 years ago

Posts: 2636

19/11/2024 11:17 am

I think you were wise to run the pump as a precaution, if the image is your garden, then very wise! In the south east, we have had an overnight low of 1 degree C. but our system has anti-freeze valves and we keep the heat pump on 24/7 anyway.

I take it you do not have anti-freeze valves at the back of the heat pump? I also imagine that this is a temporary precaution and your installers are returning soon to mix in the glycol for you? Regards, Toodles.

Toodles, heats his home with cold draughts and cooks food with magnets.

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bontwoody

(@bontwoody)

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19/11/2024 11:31 am

@lokisam

It probably isn’t a major issue as unless the heat pump actually loses power it will run the pump to stop freezing.

As toodles points out quite a few of us run without antifreeze but use anti frost valves. Some even don’t bother using them for the reason I mention above.

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

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Lokisam

(@lokisam)

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Topic starter 19/11/2024 12:54 pm

@toodles yes, it was a temporary solution. I usually set it right back temp wise at night to avoid noise but when I saw the snow I remembered the glycol and did a panic Google. According to forecast we had only -1 last night but plenty of settling snow.

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Lokisam

(@lokisam)

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Topic starter 19/11/2024 12:57 pm

@bontwoody thanks. I'm probably having some adjustments made to piping so I will ask about anti frost valves. My midnight Google suggested glycol might make it more expensive to run, but I guess it's also expensive to fix if it breaks!

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bontwoody

(@bontwoody)

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19/11/2024 1:12 pm

@lokisam Yes the glycol reduces the amount of heat the fluid can hold. There is an interesting debate on whether anti frost valves are necessary and the type of water treatment required if no glycol. Personally I have valves and just use tap water in mine.

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IRMartini

(@irmartini)

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Joined: 2 years ago

Posts: 80

19/11/2024 1:44 pm

Posted by: @bontwoody

↑

Personally I have valves and just use tap water in mine.

Same here

And yes when the temp drops low enough even when its off the heat pump runs the water pump every hour by the looks of it:

above 7 deg

6deg or lower seems to be the trigger point for the pump to run

“Anything worth doing, is worth doing right.”

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bontwoody

(@bontwoody)

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19/11/2024 2:15 pm

@irmartini always good to see what I thought was happening does 😂

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Transparent

(@transparent)

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Posts: 3093

22/11/2024 9:26 am

Posted by: @lokisam

↑

I'm probably having some adjustments made to piping so I will ask about anti frost valves.

Read this Topic which discusses anti-freeze valves and glycol.

Either strategy has deficiencies which need consideration before you start waving cash in front of an installer.

Save energy... recycle electrons!

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Lokisam

(@lokisam)

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Topic starter 22/11/2024 12:08 pm

@transparent thanks. I'll look into it.

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IRMartini

(@irmartini)

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Posts: 80

27/11/2024 2:39 pm

I've only just noticed that when it runs the pump its using DHW circuit, which makes sense as the DHW temp is likely to be hotter than the central heating circuit especially once its been off for a few hours.

“Anything worth doing, is worth doing right.”

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