Homeowner receives two $31,000 heat pump estimates, but a major mismatch prompts warnings

"When there’s such a wide difference in ASHP sizing estimates, I’d ask for a third quote."

A U.K. homeowner comparing two HVAC estimates of about $31,000, or £23,000, discovered that the installers had very different views on what the property required.

The homeowner turned to Reddit’s r/UKHeatPumps community for help interpreting the conflicting quotes.

What readers should know

In the Reddit post, the original poster described a five-bedroom home finished in 2011. The property reportedly has good insulation and roughly 3,200 square feet of living space.

The poster explained, "Both quotes I got were around £23k for [the] heat pump. One assumed a 10kW heat pump, 19 new radiators and all new plumbing. The other said 10kW wouldn't touch the sides for the house size so quoted for 17kW heat pump, 19 new rads but said plumbing was fine."

Commenters quickly cautioned that a larger unit may not be the better option. One user said, "With a big gap between the ASHP sizing estimates I would get a third quote. Some firms routinely oversize. Bigger isn't necessarily better because a big unit won't modulate down so well and will revert to stop start operation, which is inefficient."

Another commenter agreed, saying that "the 17kW heat pump sounds massively oversized to me."

The top comment added, "I think you need one or two more quotes. You have a big difference in the estimated heat loss, and also a big difference in the approach taken to the plumbing. It's somewhat unlikely that the plumbing really needs replacing, and similarly unlikely that you actually need a 17 kW unit for a modern house - even a large one."

Even with the skepticism in the comments, upgrading heating and cooling can be one of the most effective ways to reduce utility bills and guard against higher energy costs. Palmetto helps homeowners navigate newer, more efficient HVAC and heat pump choices. Its Comfort Plan network also connects homeowners with vetted installers and efficient solutions so they do not have to work through the process alone.

What can be done?

To determine the home’s actual heating needs, commenters recommended a proper heat-loss survey, along with more quotes.

Suggested starting points included Eon’s fixed-price quote service and a Heat Geek Zero Disrupt survey. Others suggested looking into Octopus and asking installers to explain why their recommendations for radiator and plumbing work were so different.

For homeowners who want to upgrade but are not ready to pay everything upfront, Palmetto’s Comfort Plan offers $0-down options that can cut heating and cooling costs by up to 50% and include 12 years of free maintenance.

Homeowners can also combine solar panels with electric appliances, including efficient HVAC systems, to reduce utility costs even further. EasyHome makes it simple to compare solar options and find the best solar system and installer for a home and budget.

Where can I learn more?

Other U.K. homeowners have also had trouble making sense of heat pump quotes.

• Another U.K. homeowner received heat pump recommendations ranging from 2.9 to 6 kilowatts, which raised doubts.

• In Glasgow, a homeowner was quoted £18,000 for a heat pump, prompting warnings about possible overcharging.

• A U.K. homeowner described shopping for a heat pump as a minefield after quotes ranged from £4,000 to £12,000.