Retrofitted (new) boiler on 70's central heating system. Something wrong with it?

N64

Hey folks,

Recently, our gas fueled boiler failed, so we got a new one installed. It was retrofitted on a central heating (i.e. single radiator and hot water) system dating back to the 1970's.

The plumber informed us that at the time, the new boiler was way more efficient than the 15+ year old one we've had before and that we should notice a reduction in energy bills.

The thing is… we haven't really noticed much of a difference from the consumption of gas being used! I've observed that the gas burning pilot light on the display is indicating that it's consistently lit, even when we've the target temperature set to 60c. No problem with the water being really warm but could something POSSIBLY going wrong here with the 4 month old system from the configuration POV?

I do recall even with our boiler of 15 years old, the gas burning would go on and off and not be lit consistently.

Our house is 200+ years old, so energy efficiency is **** and I acknowledge that.

Markcheese

Do you still have just a single rad and the water heater ? Or am I reading that wrong.. ?

Running your new gas boile (likely a condensing boiler) at 60⁰c is likely too hot to get full efficiency, you need to turn the temperature down , ( it will take longer to heat the room though) .

Do you have an open fire and back boiler ? Is the back boiler still connected to the heating system? Ie. Does your gas boiler heat your back boiler+ when a fires not lit ?

10-10-20

If it's still just the single rad and cylinder then the boiler will be cycling continuously and won't perform massively better than a 15 year old boiler anyway.

blackbox

Did you mean multiple single radiators?

Lenar3556

https://www.boards.ie/discussion/2058402835/retrofitted-new-boiler-on-70s-central-heating-system-something-wrong-with-it

There is unlikely to be a major efficacy gain in a gas boiler from 15 years ago vs one installed today. Those from 15 years ago were already pretty good.

One possible reason for longer run times is that the new boiler is smaller than the previous (and using less gas per hour of operation) In order to achieve the best condensing effect, the installer may have downsized from the previous model, and this is perfectly acceptable.

I don’t concur that a flow temp of 60 is too high, I would suggest it need to be at this point at a minimum in your case.

DublinDilbert

new boiler will typically modulate down, so although the burner will be lighting it will not be burning the same amount of gas. The old boiler would cycle on/off based on the return temperature, where as the new one will stay lit, but modulate the output down to the demand of the property.

N64

Thanks for the advice and comments everyone. I'm a newb to the plumbing world and trying to help my old mam!

Yeah. Our boiler feeds both the radiators and hot water tank. No individual controls for the radiator heating / hot water from the boiler side. Just one master temp setting.

This might be a silly question… in a old system like ours, does turning off a radiator in a given room make a difference really from the gas usage perspective? Presumably there's hot water returning to the boiler (it's in a loop?) and the closer it is to the set temperature (in our case 60c) the better? When a rad is "turned off", the hot water just bypasses it?

Any other tips generally or things we could invest in? Doubt that that the likes of a nest would make much sense in a old, drafty house!

Thanks again folks.