Volumiser required on Grant R290 air source heat pump? - Air Source Heat Pumps (ASHPs)

RE: Volumiser required on Grant R290 air source heat pump?

Patrick — Thu, 12 Feb 2026 08:32:50 +0000

@judith Indeed it's similar to the UK. It has to be an SEAI registered installer(no guarantee of competency) and the house must reach a minimum level of energy efficiency after the works are completed.

I spoke to our plumber who said he can't even install a heat pump on his own house as that won't qualify for the grant. So he needs to get another registered installer to do it.

RE: Volumiser required on Grant R290 air source heat pump?

Max Abbey — Sun, 01 Feb 2026 19:59:50 +0000

@grahamf Indeed looking at R290 models only. It will be a good while until I actually get to interpret the controls but thank you in advance

RE: Volumiser required on Grant R290 air source heat pump?

JamesPa — Sun, 01 Feb 2026 19:44:33 +0000

My understanding is that volumisers should be installed on the return circuit, not the flow?

There is a thread from a year ago where this was debated at length and the conclusion, well argued imho, was flow is better but it's likely only to make a difference in a relatively small minority if cases, and the difference will be a marginal comfort one.

RE: Volumiser required on Grant R290 air source heat pump?

GrahamF — Sun, 01 Feb 2026 19:42:16 +0000

I have a Grant Aerona R290 15.5kW heat pump, which is running very nicely. Certainly don't go for the Aerona3 R32 heat pump or its antiquated controller.

I would be happy to help you with how to use the Aerona R290 Smart Controller.

RE: Volumiser required on Grant R290 air source heat pump?

GrahamF — Sun, 01 Feb 2026 19:39:06 +0000

@jamespa I agree that it is important to avoid a 4 port buffer or low loss header, due to the impact on efficiency.

My understanding is that volumisers should be installed on the return circuit, not the flow?

RE: Volumiser required on Grant R290 air source heat pump?

Max Abbey — Sun, 01 Feb 2026 19:05:53 +0000

If it follows other grants here, then, as before, you have to use a registered contractor. And like in the UK there is no guarantee as regards quality etc
It puts me off using grant assistance in most cases but at that level of support I will look more seriously into it.

There is one other really good scheme here for vacant homes. If the house is over 2 years not lived in then there is a max of €50k for bringing it back into habitable use. This grant does allow for DIY (with local authority oversight) so that sum can be pretty much parts only support.

RE: Volumiser required on Grant R290 air source heat pump?

Judith — Sun, 01 Feb 2026 17:31:54 +0000

Great news this week too. The heat pump grant here has increased from €6500 to €12500.

Thats generous! Does the small print of the grant allow DIY? In UK it has to be a MCS registered professional( doesn’t guarantee competence) and replacing an existing fossil fuel boiler.

RE: Volumiser required on Grant R290?

Max Abbey — Sat, 31 Jan 2026 12:09:04 +0000

@patrick That is great news, must chase that up, Thanks

RE: Volumiser required on Grant R290?

Patrick — Sat, 31 Jan 2026 08:01:38 +0000

@max-abbey hey! That's super cool, so nice to hear from other like minded people in Ireland! Do keep us posted, will be very interested to hear how you get on.

Would love to go on the grant course myself as well if they'd have me. Although I chose to leave the installation to a plumber, just because we've got other work going on and I wouldn't trust myself to be done fast enough to get out of the way of the builders.

Great news this week too. The heat pump grant here has increased from €6500 to €12500.

RE: Volumiser required on Grant R290?

Mars — Mon, 26 Jan 2026 23:06:09 +0000

@max-abbey, absolutely, but it’ll also be so interesting to see how much cheaper it’ll be than the standard-ish going rate for heat pumps install.