Letters

Intouch Please send your letters, which may be edited, to editorial@registeredgasengineer.co.uk.

What about weather compensation?

Reading last month’s Registered Gas Engineer, I see that you have tried to explain weather compensation: I have to say that your definition is quite incorrect.

The purpose of weather compensation is to adjust the flow temperature in line with the outside air temperature. As the air temperature outside increases, the house needs less heat because there is less heat loss through the structure. To achieve less heat, the flow temperature is reduced. This has a knock-on effect in a condensing boiler because it means that more latent heat can be extracted from the exhaust gases.

Latent heat is when the hot water vapour (exhaust gas) condenses into condensate water. When this happens, latent heat is given out, which passes through the heat exchanger to the incoming return water, which is at a low temperature. The lower the return water temperature, the greater the harvesting of latent heat from the exhaust gases and hence the greater efficiency.

The greatest benefit of this system, as opposed to just turning down the flow temperature, is that the boiler’s computer is making this calculation every second and optimising the flow temperature.

The result is a house that feels much more comfortable because the heat in the rooms is gradually increased or decreased in line with the outside temperature rather than starting up and shutting down with a traditional internal room stat. The benefits are about a 5 per cent or more energy saving, which could, in some houses, equate to £100 per year.

All system boilers with weather compensation systems also have a system where they revert to high-temperature heating when recharging a cylinder: this is to allow the cylinder to quickly reach its set point of say 55°C.

Weather compensation controls can be fitted to most existing boilers of about 10 years old. Richard Weir, Boiler Bee

From the editor: Last month’s article ‘How can you help cut your customers’ heating bills’ is a simple guide that gas engineers can use to discuss possible energy-saving measures with their customers. We did not go into detail about how any of these measures work, particularly so on weather compensation, which Mr Weir explains so clearly.

We’re all acutely aware of the current pressure on household budgets, and these measures are suggestions on how your customers can use less energy – and, in turn, save money.

Photos must show best practice

You produce a great publication which keeps me up to date on good practice for when I teach the ACS courses at a number of centres.

I know you use stock photographs for your articles but they should be checked for good practice, otherwise the people who read it may think this is the way it should be done because it’s shown in your publication.

When you look at the photograph [page 24, April 2022, ‘Become an approved meter installer’] there does not appear to be any access to the regulator should it need adjustment and/or to re-attach the security wire. The main cause for concern, however, is the fact that the meter control valve appears to fall to on, which goes against the Gas Safety Regulations.

Any stock photos where good practice is not shown should be mentioned in the text somewhere with an explanation. Rodney Briddon C Eng

From the editor: Thank you to those readers who pointed out that the stock picture accompanying this article was not appropriate. The article was written by our friends at ElectraLink, who also provided the picture, but we agree that this particular image should not have been included and we will make sure that images supplied to us by external contributors are checked carefully.

ElectraLink says: “Upon investigation, we have found that the image provided by ElectraLink was a stock photograph selected by a non-technical team member and the non-compliant nature of the meter was not recognised. ElectraLink did not intend this stock image to represent a compliant meter, and upon realisation that it does, ElectraLink has removed the photo from its stock library and will refrain from using images with this level of technical detail in future.”