# Questions to ask before you sign Eleven questions, what a good answer sounds like, and what a bad one tells you. Print it, take it to the appointment. - Kind: Guide - Written for: I intend to buy (ready to get quotes, or holding one already) - Category: Paperwork and permissions - Updated: 2026-09-06 - Canonical address: https://ampworth.com/guides/questions-to-ask-before-you-sign > **In short:** Ask to see the room-by-room heat loss calculation, the water temperature the heat pump is designed to run at, the five figures behind a solar estimate, and what is not included in the price. A good installer answers with specifics. Vague answers mean the design work has not been done. You are not trying to catch anybody out. A good installer will answer all of these easily and will be glad you asked, because it means the rest of the conversation can be a real one. What you are listening for is whether the answer is specific, because specificity comes from work already done. ## About the design ### "Can I see the room-by-room heat loss calculation?" *Heat pumps.* A good answer hands it over, or says when it will exist. A bad answer explains why a house like yours does not need one, and the standard makes no such exception. ### "What flow temperature is this designed for?" *Heat pumps.* This is the temperature of the water the heat pump sends round the radiators. A good answer is a number: "45 degrees." A bad answer is "low temperature", or a look of mild surprise. ### "Which room needs the hottest water, and what would it cost to change that radiator?" *Heat pumps.* This is the question that separates people who have done the design from people who have priced a box. The whole house runs at whatever temperature its worst room demands, so one undersized radiator sets your bill. A good answer names the room. A very good answer has already priced the alternative. ### "What five numbers did you use for the generation estimate?" *Solar.* Capacity, postcode, pitch, direction, shading. A good answer lists them. A bad answer says it comes from their software. ### "Did somebody go and assess the shading, and what did they find?" *Solar.* A good answer describes what was found, including the chimney. A bad answer is "there is no shading" from somebody who has seen a satellite photograph. ## About the numbers ### "Is that saving figure based on what I generate, or what I use myself?" *Solar.* These differ by a factor of three or four. A good answer distinguishes them without hesitating, and knows roughly what proportion you would use. A bad answer treats them as the same thing. ### "What are you assuming I pay for electricity and gas?" Every saving figure rests on two prices. A good answer states them and will happily redo the sum with yours, and a bad answer cannot say what they are. ### "What does this heat pump deliver on the coldest day, at the flow temperature you have designed for?" *Heat pumps.* Not the headline rating. A unit sold as 8 kW can be 5.5 kW at the conditions that matter. A good answer knows the difference and has the figure, and a bad answer repeats the headline number. ## About the job ### "What is not included in this price?" An open question, deliberately. A good answer volunteers the awkward ones: scaffolding, an electrical supply upgrade, making good, taking the old system away. A bad answer is "everything is included", which is never quite true. ### "What happens if you find something unexpected after you start?" Something usually is found. A good answer describes how it would be raised with you and priced before it is done. A bad answer is that it never happens. ### "Who stands behind the workmanship if you are no longer trading?" A good answer names the insurance-backed guarantee provider and offers the policy. A bad answer is a reassurance about how long they have been in business, which is not the same thing and does not survive an insolvency. ## Signs of good answers Across all eleven, the pattern is the same. Somebody who has surveyed your house and designed a system can answer in specifics without reaching for anything. Somebody who has looked up a house of roughly your size in a table will answer in generalities and move the conversation towards the price. While they are there, ask yourself two more questions. **Did they tell you anything you did not want to hear?** Almost every house has something: a radiator that needs changing, a shaded corner of the roof, a supply that needs upgrading. Somebody who found nothing at all either did not look, or is not telling you. **Did they ask to see your bills?** A year of your own consumption is the best information available about your house. An installer who does not ask for it is quoting on estimates. ## After the appointment Do not decide in the room. Consumer law gives you a cooling-off period on a contract agreed at home, and any pressure to sign before you have read it is a reason to slow down, not speed up. Get the answers in writing. "Yes, the flow temperature is 45" said in your kitchen is not the same as a design document, and it is the document that gets installed. ## Sources - MCS Customer Commitment, The commitment made to customers: https://mcscertified.com/standards-library/ - MIS 3005-D, Heat pump systems: design: https://mcscertified.com/standards-library/ - MCS 001-1, Scheme requirements for contractors: https://mcscertified.com/standards-library/ ## Related - [What a good quote looks like](https://ampworth.com/guides/what-a-good-quote-looks-like.md): A quotation should show its working. What ought to be in one, what the gaps usually mean, and the handful of numbers that matter more than the price. - [Comparing quotes that look nothing alike](https://ampworth.com/guides/comparing-two-quotes.md): Quotations for the same house rarely arrive in the same shape. A method for putting them side by side, and what a big difference in price usually turns out to be.