Urgent Glycol Question - Air Source Heat Pumps (ASHPs)

RE: Urgent Glycol Question

IRMartini — Wed, 27 Nov 2024 14:39:34 +0000

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.

RE: Urgent Glycol Question

Lokisam — Fri, 22 Nov 2024 12:08:59 +0000

@transparent thanks. I'll look into it.

RE: Urgent Glycol Question

Transparent — Fri, 22 Nov 2024 09:26:47 +0000

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.

RE: Urgent Glycol Question

bontwoody — Tue, 19 Nov 2024 14:15:37 +0000

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

RE: Urgent Glycol Question

IRMartini — Tue, 19 Nov 2024 13:44:13 +0000

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

9041

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

9042

RE: Urgent Glycol Question

bontwoody — Tue, 19 Nov 2024 13:12:45 +0000

@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.

RE: Urgent Glycol Question

Lokisam — Tue, 19 Nov 2024 12:57:42 +0000

@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!

RE: Urgent Glycol Question

Lokisam — Tue, 19 Nov 2024 12:54:20 +0000

@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.

RE: Urgent Glycol Question

bontwoody — Tue, 19 Nov 2024 11:31:08 +0000

@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.

RE: Urgent Glycol Question

Toodles — Tue, 19 Nov 2024 11:17:12 +0000

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.