Does boiler efficiency get worse over time?

[kidgreen61]

I always make the point to customers, that changing the boiler to a newer, and therefore less reliable boiler isn't always the way forward.
In your case, let's for argument sake say it will cost you £2k to change your boiler, it will take an awful long time to recoup that outlay, when your new boiler will still be using gas, albeit a little less.
£2k buys a lot of gas.
Your old boiler will probably go for another 10yrs, by which time you may decide to move house, and save yourself a load of money.

A good many new boilers are getting tired after 10yrs, and may require expensive parts, or replacement.

Only my opinion as an installer, no offence meant to others.

 

[Ltnman]

As I have a CH output of 50C with a return temperature of 33C my combi boiler should have an efficiency of around 96%. It is a modulating boiler with smart controls with various temperature thresholds set throughout the day and night. As I don’t have a tank we are not heating water unnecessarily. Daily average consumption for HW only is around 3kw for the 4 of us. Much of that saving comes from an aerating shower head that gives the impression of a high powered shower but is only using 5.1 litres of hot water a minute. The hot water temperature is set for 42C so we add very little cold.

 

[gerbils]

I always make the point to customers, that changing the boiler to a newer, and therefore less reliable boiler isn't always the way forward.
In your case, let's for argument sake say it will cost you £2k to change your boiler, it will take an awful long time to recoup that outlay, when your new boiler will still be using gas, albeit a little less.
£2k buys a lot of gas.
Your old boiler will probably go for another 10yrs, by which time you may decide to move house, and save yourself a load of money.

A good many new boilers are getting tired after 10yrs, and may require expensive parts, or replacement.

Only my opinion as an installer, no offence meant to others.

Thank you - that is helpful to know, especially as we'd be looking nearer £4k.