17kw Grant Aerona heat pump not performing
It really sucks Sonix, you've tried to do the right thing and been badly let down. I would be surprised if the plate heat exchanger is badly blocked, to the point the primary flow is seriously restricted. It would have to take a hell of a lot of quite large particulate contamination to do that, or some massive scale build up due to some water quality issue. Grant ASHPs don't have particulate strainers on the inlet return water connection. The magnetic sludge that builds up on ferrite magnet cores is very fine - too fine for particulate strainers, which is why magnets are used. Reverse flushing using various chemical agents should clear it. The brazed plates are stainless steel, but check compatibility of rubber hoses, plastic pump housings and impellers, etc., before chucking aggressive flushing and cleaning chemicals inside it.
My hunch is an issue with the primary circulating pump. It's relatively easy to remove for inspection change out, and a competent plumber could do that. A primary pump replacement is not new monobloc territory cost. You wouldn't change out a combi for a failed circulating pump, so surely it's not unreasonable to expect Grant to hold circulating pumps as a spare part? Even if they don't the pump will be a generic product and you may be able to source a replacement yourself. Grant are stockists of badged up Chofu units, probably with little spare parts holding in the UK. Dare say they'll probably advise changing the whole monobloc for relatively minor component failures which could and should be repairable.
The grant pump isn’t pwm controlled so you could literally fit the cheapest one from toolstation and it would work without error codes.
Off grid on the isle of purbeck
2.4kW solar, 15kWh Seplos Mason, Outback power systems 3kW inverter/charger, solid fuel heating with air/air for shoulder months, 10 acres of heathland/woods.
My wife’s house: 1946 3 bed end of terrace in Somerset, ASHP with rads + UFH, triple glazed, retrofit IWI in troublesome rooms, small rear extension.
Grant have now agreed to replace the circulating pump to see if that's that root cause of the issue this week as it's been power flushed twice with fx2 and another stronger chemical already and the water didn't look that dirty according to the heat engineer. He was expecting it to be black and it wasn't that bad he said. The power flush is using a Kamco flush which has a flow of 200lpm. So fingers fingers crossed it's the pump at fault.
@hughf sorry what does pwm controlled mean? The Grant pump is a pretty powerful pump with 12m head I'm told and as it's the only pump we have now it would need to be at least as powerful.
- 26 Forums
- 2,114 Topics
- 46.4 K Posts
- 116 Online
- 3,410 Members
Latest Posts
-
RE: No-code, plug-and-play monitoring for your heat pump
Ours arrived a couple of days ago as it happens and pla...
By benson , 8 minutes ago
-
RE: Benefits of an extra horizontal loop for GSHP
It will improve performance, but by how much depends on...
By Brendon Uys , 3 hours ago
-
Is this just haze or something more?
We clocked this article back in July from the BBC about...
By Mars , 4 hours ago
-
RE: The good, the bad and the not that great – my heat pump installation
Said I would pop back with a update. Only Mr Jesus h...
By Burtis , 17 hours ago
-
RE: Buffers, hot water and cooling
Thats presumably heat pump DT, what about radiator DT a...
By JamesPa , 18 hours ago
-
RE: Who's your electricity provider and what's your tariff?
@chandykris Exactly the same here. We now have 13.5kWh ...
By Old_Scientist , 1 day ago
-
Compressor and Evaporator Stratification
I have had a few issues with my Hitachi spilt heatpump ...
By trebor12345 , 1 day ago
-
RE: Wood burner with ASHP - direct air?
This depends on the size of your wood burner and size/t...
By Lucia , 2 days ago
-
RE: Difficult positioning of air source heat pump
@rikiarn It's a not a buffer it's a volumiser which is ...
By Lucia , 2 days ago
-
RE: Is your heat pump insured?
To make things clear, lots of insurance companies cover...
By Lucia , 2 days ago
-
RE: Boxt Heat Pump Installation Experience
@adrian any updates since installation? How is it perfo...
By Ashfp , 2 days ago
-
RE: Say hello and introduce yourself
Hi @seatonian - Yes, I know Seaton, and I have the Nat...
By Transparent , 3 days ago
-
@seatonian got your email. Will connect you with a reco...
By Mars , 4 days ago
-
@downfield and @toddles, this isn’t in the settings cur...
By Mars , 6 days ago
-
RE: Homely launched for Grant Aerona ASHP control
I haven't bought the Aerona Smart Controller (£700!) bu...
By Prunus , 6 days ago
-
RE: Antifreeze top up for my heat pump - is this a rip off?
For the record, Grant supply ethylene glycol for their ...
By Prunus , 6 days ago
-
RE: Compressor attempts start but fails - Nibe Fighter 2005 8kW
@skyefarmer amazing. Well done!
By Mars , 6 days ago
-
RE: Air source heat pump roll call – what heat pump brand and model do you have?
Ebac 5kw - Monobloc R32. Developed and made in UK - Mit...
By marcinwloch69@gmail.com , 1 week ago
-
RE: Is a Valliant Inline 6kW heater a BUS buster?
Just another thought - it might be worth thinking about...
By JamesPa , 1 week ago
-
RE: BUS Grant: removal of all other fossil fuel heat sources
@rikiarn - just have a think as to how much it will cos...
By Transparent , 1 week ago