Stefan Clarkson, 46, and his wife Diane, 49, applied for a £10,000 Green Homes Grant to replace their inefficient 20-year-old boiler and all their radiators.
Work was supposed to start on June 28 - and government-approved workmen removed their old boiler and all their radiators in preparation just days before.
They didn't arrive before the £10,000 voucher expired last Tuesday (November 30).
Mr Clarkson, who is disabled and has a heart condition, couldn't find any other suppliers - who must be approved by the government scheme - to carry out the work earlier.
The family, including stepson Lewis, 29, and daughter Théa, 13, have had to move into a friend's home.
They haven't got any savings, and only went forward with the renovation work under the government eco scheme because the qualified for a voucher for 100% of the costs.
Worse still, they were forced to remove the boiler themselves as the installation company claimed this was outside their remit.
Mr Clarkson from Skelbrooke, Yorkshire, said he has appealed, but has been told no extension will be granted.
The dad-of-two said: "The boiler has been removed, I've literally got nothing - I may as well live in a warehouse.
"I'm lost for words - I don't know what to do.
"The Government have totally refused to extend the voucher in any way, shape or form.
"I've even told them that it's obviously making me a bit ill, I suffer from mental health issues and severe disability - and they just don't care.
"I feel as though I've been cheated, that through this whole scheme which is supposed to help you go green and give you a better heating system that now I've ended up with nothing.
"I just feel as though I've let my family down, because there was already an adequate heating system before, and the only reason I've done this is that the grant was available.
"I can't afford to put anything back in now."
Mr Clarkson was granted £10,000 to replace all the radiators and boilers in his four bed bungalow.
The installers cancelled last minute twice over summer and again last week.
He said they blamed shipping delays from China during the global shipping crisis this year.
Mr Clarkson, who is almost immobile and suffers from depression and thyroid issues, said: "It was all quoted up through one of their approved suppliers last year.
"Obviously coronavirus came along and so there were all the delays that came with that, but then when it came down to installation they let me down right at the last minute.
"Originally they said they couldn't source the materials, originally the cylinder, because of the world wide shipping crisis so they couldn't get enough steel to make the units - so there was a delay getting that.
"That just went on and on and on for some months, I just couldn't get hold of them.
"Eventually, I accepted an alternative cylinder which didn't match because there was no alternative, so that was booked in again - and then right at the last minute that was cancelled last week.
"Now they cant get the heat pump either, so they've said they don't know when they're going to be available again and can't make any guarantees - so they're not going to be able to install before the 30th November".
The Green Homes Grant initiative is part of the Government's general drive to replace inefficient boilers, providing grants to low-income families of between £5,000-£10,000 as part of a controversial effort to reduce Britain's carbon footprint.
The project has been criticised for forcing families to pay for expensive boiler improvements despite owning adequate boilers still.
The government website for the scheme says: "No vouchers will be extended beyond 30 November 2021."
Despite appealing for more time, Mr Clarkson has so far received a flat 'no' for any further help or extensions past the 30th and is clueless over what to do.
He said: "As part of the workup to having this installation done, the existing heating system has now been removed. So I've not got a heating system anymore.
"They've left me in a state - they just don't care. I just feel absolutely lost".
The Department for Business, Energy & Industrial Strategy, which administers the Green Homes Grant, has been contacted for comment.