Is it possible to upgrade a gas system boiler to combi in an apartment?

VonLuck · 16-03-2023 04:59PM #1

Hopefully a straight forward question. I currently live in an apartment and have a standard gas boiler (with pressure gauge) that heats a water tank for both my central heating and hot water needs. I also have an immersion switch which I have never used. The boiler is about 15 years old now so it's likely due an upgrade. I find I have to top up the water pressure regularly and my gas usage has been higher than I'd like.

The main issue really is that I'm heating a large tank of water in the morning just to have a small bit of hot water before going to work. All that energy is wasted in heating water that I don't get to use.

I thought about switching to a combi-boiler as I understand you get hot water on demand. Is it possible to have this kind of boiler in an apartment? I assume all my current pipework is buried in the floors / walls and I won't be able to modify their routing. Is it a case that all the existing pipework can be reused and I just need to switch out my boiler?

Someone mentioned to me that I could also remove the tank in my hot press which would be great to free up some space if possible.

10-10-20 · 20-03-2023 12:26PM

Yes, as long as the existing boiler and hot-press locations are relatively close to each other - that's do-able and a good idea. There are some specifics which you would need to get into with a plumber onsite through, but all of these should be resolved with some additional pipework within the hot-press, but it should be a simple enough job.

VonLuck · 20-03-2023 02:43PM

https://www.boards.ie/discussion/comment/120378741#Comment_120378741

Thanks for the response. Really appreciated.

Why do the hot press and existing boiler need to be near each other if there's no longer a need to hot water storage? Unfortunately my hot press is on the opposite side of the apartment from where my boiler is locate. Maybe 8 metres as the crow flies.

10-10-20 · 20-03-2023 02:49PM

https://www.boards.ie/discussion/comment/120379307#Comment_120379307

Because combi's have two hot water feeds: domestic hot water and central-heating water. So you'll need a pipe to take the domestic hot water from the combi into the existing taps, usually at the location where the cylinder was removed. That's the tricky part, or not - depends on the installation.

thebiglad · 20-03-2023 02:52PM

I had a combi installed some years ago (Duplex Apartment) - I completely removed the hot water tank and also removed the hot press to make more bathroom space. Only hot water now is on demand - boiler has broken down once (it is serviced annually) so has not been a problem yet - we have an electric shower in the en-suite though. Pipework had to be rerouted but I took the chance to renew the pipework, had a couple of leaks prior due to shoddy building standards by the developer so it made sense on many levels for me.

10-10-20 · 20-03-2023 03:25PM

Deleted: posted to wrong thread.

VonLuck · 20-03-2023 04:48PM

https://www.boards.ie/discussion/comment/120379349#Comment_120379349

Ah okay, but does a standard boiler not have two feeds as well to serve hot water and central heating separately? Apologies for the possibly basic questions!

10-10-20 · 20-03-2023 04:53PM

No, a boiler will only have one supply and an external valve (if fitted) directs that one supply to either the tank coil or to the rads.

VonLuck · 20-03-2023 05:26PM

https://www.boards.ie/discussion/comment/120380074#Comment_120380074

Sounds like a bigger operation that I originally thought. To route a whole new run of pipes to my hot press seems impractical for an apartment building! Such a shame too as it would be perfect for my current hot water usage.

Is it possible to upgrade a gas system boiler to combi in an apartment?

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