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10 Questions to ask when choosing your air source heat pump installer

Posted by John Lightfoot on 28 November 2011 at 9:13 am

1. Are you MCS certified?

The Government is currently offering incentives (Renewable Heat Premium Payment) to people who install renewable energy heating equipment, including air source heat pumps, if your property does not have access to mains gas. It is also considering offering further financial support through the Renewable Heat Incentive, which will be payable from 2012, for renewable technologies installed into residential properties. In order to take advantages of these financial incentives both the product and the installation company must be certified under the Microgeneration Certification Scheme (MCS).

2. How many air source heat pumps have you installed?

There are, of course, many very capable and highly experienced installers that are not MCS accredited and therefore perhaps another question to ask is "how many ASHPs have you installed?".

3. Do you have customers I can talk with who have experience of providing their heating / hot water with a heat pump?

It can be useful to talk to someone who has experienced using a heat pump to heat their home and their domestic hot water; if only to be reassured that it works! [and check to see if the installer has been recommended on YouGen - Ed]

4. Could you explain how you would choose the best heat pump for my installation and why?

This discussion can bring to light any difference in what your installer believes are your priorities and what you consider them to be. It will also help reassure you that your installer knows what he is talking about.

5. What is lowest ambient temperature the proposed heat pump will cope with and what will you do to ensure I have adequate heat below this level?

This will help you understand exactly how much of your heating the installer is planning your heat pump to supply.

For your information the design temperatures specified in Microgeneration Installation Standard: MIS 3005 for different areas of the UK are as follows:-

Belfast: -1.2C
Birmingham: -3.4C
Cardiff: -3.9C
Edinburgh: -1.8C
Glasgow: -3.9C
London: -1.8C
Manchester: -2.2C
Plymouth: -1.2C

6. How do you plan to deal with hot water pasteurisation or the “legionella” issue?

Legionella bacteria can breed in water with temperatures between 25C and 45C and if particles of water containing the bacteria are breathed in, when having a shower for example, it can cause illness. The bacteria will however die within a few minutes if exposed to temperatures over 60C. The domestic hot water therefore has to be raised above this temperature, normally once a day, to ensure the bacteria has no chance of surviving.

Other questions to ask that probably do not need any explanation are:

7. What warranty do you offer?

8. Can you advise on planning issues?

9. Can we use our existing hot water tank?

10. What are the noise levels of the heat pump you are proposing?

Photo by Horia Varlan

About the author: John Lightfoot is director at Thermal Energy Ventures Ltd.

If you have a question about anything in the above blog, please ask it in the comments section below.

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3 comments - read them below or add one

Antony Way

Antony WayComment left on: 17 January 2017 at 12:15 pm

My installer has recommended a Swedish ground heat pump. He says it's the best any ideas on how I check this?

what are the Rolls Royce of heat pumps?

any help much appreciated 

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nnw49Comment left on: 28 November 2011 at 11:42 am

I think I'd also be asking about the radiators (assuming it isn't possible to fit underfloor heating in a retro-fit):

- if the system is reusing existing (maybe from an oil boilered system) rads what is going to be done to them

- if a new set it being fitted then how are they being sized

How much overcapacity is there in the whole system to cope with the heatloss being greater than theoretical?

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Bob Irving

Bob IrvingComment left on: 28 November 2011 at 9:46 am

An interesting question to ask him would be how he checks that the ASHP is performing OK when it's installed. How do you make sure that these systems are working at their rated COP?

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