Questions to Ask a Heat Pump Installer as a Landlord

Survey and room-by-room heat-loss calculation

Ask for a heat-loss calculation for every room, not a rule of thumb per square metre. It decides the size of the heat pump and of every radiator, so a quote without one is a guess.

Put these to each firm:

• Will you visit the property and measure it, or work from the EPC and photographs?
• Can I see the room-by-room figures, including the assumed air change rate and the U-values you used?
• What did you assume about loft and wall insulation, and would the sizing change if I insulated first?

The last question matters. If cheaper insulation work would shrink the heat pump you need, that is worth knowing before you order the larger unit. What to settle first is covered in before you install a heat pump in a rental.

Design flow temperature and SCOP

Ask what water temperature the system is designed to run at and what seasonal efficiency (SCOP) the installer expects. The two numbers go together: a lower flow temperature gives a higher SCOP and a lower bill.

SCOP is the heat delivered per unit of electricity over a year. This matters because of the price gap. On the Ofgem cap for 1 October to 31 December 2026, electricity is 26.32p per kWh and gas is 7.97p per kWh. Modelled arithmetic: heat from gas at 90% boiler efficiency costs about 8.9p per kWh, while heat from a heat pump at SCOP 3.0 costs about 8.8p, and at SCOP 3.5 about 7.5p. A design that only reaches SCOP 2.5 costs more to run than the gas boiler it replaced.

So ask:

• What design flow temperature, and what SCOP does that give for this house?
• What is that estimate based on, and is it in the written quote?
• Will the system use weather compensation?

Radiators

Ask for a list of every radiator that will be replaced or kept, with its output at the design flow temperature. Heat pumps run the water cooler than a gas boiler, so many existing radiators are too small, and that is a common reason for cold rooms in the first winter.

• Which radiators stay, which are swapped, and which need new pipework?
• Does the price include making good where pipes are moved?

Cylinder size and the legionella cycle

Ask how large the hot water cylinder is, why that size, and how often the system heats the stored water to a higher temperature to control legionella. The answer affects comfort and running cost.

• What volume, and is it sized for the number of bedrooms and bathrooms, including a possible HMO or a full house of sharers?
• How often does the cylinder get its high temperature cycle, and what supplies the heat?
• Where will the cylinder stand, and who services it?

Controls the tenant will use

Ask what the tenant can change and what is locked. A heat pump works best left on a steady schedule, so a tenant who treats it like a boiler, switching it off and blasting it back on, can lose the efficiency the design relied on.

• What does the thermostat or app show, and who holds the login?
• Can the schedule be set by the landlord, with the tenant able to alter the room temperature only within a range?

Read what heat pumps cost tenants to run before you decide how much control to hand over.

The MCS certificate

Ask for the MCS certificate and the installer’s MCS registration number, and check both yourself. The Boiler Upgrade Scheme requires an MCS installer, so a firm that is not certified cannot claim the grant for you.

• Is the firm MCS certified for heat pumps now, not only for solar?
• Will the certificate for this installation be handed over, and when?
• Can I find the firm on the MCS register?

Look the firm up on the MCS “find an installer” page and follow the steps in how to check an installer. This site only publishes guidance and holds no certification.

Guarantees and deposit protection

Ask exactly which guarantees you get, who stands behind them if the firm stops trading, and how any deposit is protected. Do not accept “everything is covered” without a document.

• What is the workmanship guarantee, how long does it last, and is it insurance backed?
• Which consumer code or protection scheme do you belong to, and what is your membership number?
• How much is the deposit, and what protects it?

As one example, the HIES scheme states that its deposit protection covers up to 25% of the contract value, to a maximum of £5,000, valid for 120 days from signing, if the installer ceases trading before completing the work. That covers one scheme only, and it is not the same 120 days as the grant window. Check the wording of whichever scheme your installer names, on that scheme’s own site.

Paperwork for the Boiler Upgrade Scheme claim

Ask who applies, when, and what you need to supply. On the government’s rules the installer applies for the grant on the owner’s behalf, and the installation must be done within 120 days of applying. Landlords are eligible, but you must own the property.

Question	What a good answer includes
Who files the application?	The installer, on your behalf as owner
What do you need to supply?	A written list, agreed before you sign
What if the work runs past 120 days?	A written plan, and who bears the risk

Hybrids and a replacement for existing low carbon heating are not eligible, so ask the installer to confirm the property qualifies before any survey fee is paid. The full rules are in the landlord guide to the Boiler Upgrade Scheme.

Handover pack for the tenant

Ask for a handover pack and a walk-through with the tenant. The tenant lives with the system and needs instructions that fit a rented home.

• Does the pack include commissioning figures, the controls guide and warranty papers?
• Will someone show the tenant the thermostat, the hot water settings and what the outdoor unit sounds like?
• Who does the tenant call for a fault, and who pays?

EPC refresh after install

Ask whether the installer can arrange, or tell you how to commission, a new EPC once the system is in. An EPC lodged before the work does not show the heat pump, and a new assessment is how the register learns about it.

A heat pump does not always lift the band, and sometimes it does little for the rating on its own. This is covered in do heat pumps improve the EPC rating. Check the result on the government’s find an energy certificate service after the assessor lodges it.

When a different answer is better

Not every rental should get a heat pump today. If the walls and loft are poorly insulated, the property is a small flat with an efficient gas boiler, or there is nowhere to put a cylinder, insulation or a like-for-like boiler may be the sensible choice. A good installer will tell you that. A firm that quotes a heat pump for every house without a heat-loss figure has told you something about itself.

When you have the written answers, put them next to each other and run your own numbers in the heat pump landlord calculator.