Heat pump calculator for landlords

What to enter

The calculator has seven inputs.

• Current heating: mains gas, oil, LPG, or electric or storage heaters. This sets the fuel price and the boiler efficiency used for the baseline.
• Heat pump type: air-to-water, which uses radiators and a cylinder, or air-to-air, which heats rooms with indoor units. The type decides the grant.
• Property: a starting heat demand in kWh a year, from a small flat at about 5,000 to a large or solid-wall house at about 18,000.
• Heat demand: overwrite the starting figure if you have one from an EPC or a heat loss calculation.
• Installed price before grant: pre-filled with the Energy Saving Trust figure of around £12,000. Replace it with a real quote.
• Heat pump efficiency (SCOP): 3.0 cautious, 3.5 well designed, or 2.8, the scheme minimum for air-to-water.
• Gas disconnected: tick this if the gas supply would go, to include the gas standing charge you would save.

The assumptions behind it

Electricity and gas use the Ofgem cap for 1 October to 31 December 2026: 26.32p and 7.97p per kWh. Electricity carries no VAT from 1 October 2026 to 31 March 2027. The gas boiler is assumed to be 90% efficient. The default heat demand is the illustrative three-bedroom semi at 12,000 kWh, and flats and small terraces use much less.

Grant amounts are the ones published on GOV.UK. The calculator does not check that your property is eligible. See the Boiler Upgrade Scheme guide for landlords for the rules, including one grant per property, no hybrids, and installation within 120 days of applying.

How to read the result

The result gives you four numbers: the grant, the net cost after the grant, the heating cost now and the heating cost with a heat pump. If the bill falls, it shows a simple payback: the net cost divided by the yearly saving.

If the bill rises, the calculator says so plainly. For a home on cheap mains gas that is common, because a heat pump at a seasonal efficiency of 3.0 produces heat at roughly the same price as a 90% efficient gas boiler. A heat pump can still make sense as the way to reach EPC C, but you should not expect a saving. That matters most if you pay the bills, or if a tenant does and you hear about it.

A home heated by electric storage heaters is the strongest case, because a heat pump replaces one-for-one resistance heating.

What the calculator leaves out

It is a screening tool. It does not include:

• maintenance, servicing or the cost of replacing equipment
• the cost of new radiators, pipework, a cylinder or an electrical upgrade, unless you put them in the installed price
• time of use tariffs or solar generation, which can change running costs
• whether a heat pump is the cheapest route to EPC C, since insulation may be
• finance costs, tax treatment or lender conditions, so check your mortgage terms
• your tenancy arrangements, planning permission and the freeholder’s consent, which are covered in the pre-install checklist

It is not a quote and not advice. The cap changes each quarter, so rerun it after the next announcement.

Where to go next

If the numbers look worth pursuing, read is a heat pump worth it for landlords for the wider case, and check your EPC position with the EPC deadline checker. When you want quotes, send an enquiry and relevant independent firms will contact you, with no charge to you and no obligation.