Adjusting to a Combi Boiler

Mee

Hi All,

My apartment is scheduled by the HA for a change of boiler from a system boiler to combi boiler next year. I'm worried as I currently save money during the summer/ warmer months as the hot water remains at a good temperature for a day so thus can heat water every other day during that time. Also, on auto I have enough hot water after 20-30 minutes/day.

My understanding of the combi boiler system is that I loose my tank (but gain much needed space) and have instant hot water. It sounds great and may be I'll save water (no need to heat up a tank?) and energy somehow, but will I? Am I missing something (apart from a brain)?

I've read about the pros and cons, but just wish to know how other MSEs adapted to the change of boiler.

Thanks

JimmyChanga

I'd say you're far better off with a combi for an apartment. Only hot water when you need it and mains pressure. I would hate to go back to the tank pre-heat system.

You don't know that you save money with the current system because you're not comparing it to a combi :-) Plus you have controls to turn down how heated the water is on a combi. Likely will cost you less.

shortcrust

I suppose it depends how much hot water you use. I have a combi boiler and once worked out that a bath costs me about 15p. I spend almost nothing on gas when my heating isn’t on. Maybe two or three quid a month. But I don’t use loads. A shower and a bit of washing up every day (most?:p) plus a bit of hand washing and I’m done.

dunroving

I'd agree with the general opinion that it's cheaper because you aren't keeping a tank of water hot just for an occasional shower and washing up.

If you do get a combi, one MSE tip I'd give is this: If you have a mixer tap, make sure you are using only cold water when you only need cold water. For some unknown reason, I think a lot of people don't get this concept and when cleaning teeth, quickly rinsing hands, rinsing veg, etc. you hear the combi turning on because the mixer tap is not turned hard right (or left, depending on your set-up). Waste of energy - and money!

Tom99

Assuming your water is heated via gas at the moment rather than E7 then a combi should be cheaper for the same amount of hot water since with the existing set up you are bound to lose some heat from the stored water.
I would be more concerned about whether the output of the new combi boiler would be sufficient for a decent shower. Being an apartment the output needed for the CH side is likely to be low so the HA are likely to fit a low output boiler.

coffeehound

Mee wrote: »

and have instant hot water.

Hiya
yeah, "instant" is a subjective term. Your new boiler may have a 'keep warm' setting that switches it on every so often so that there's always some hot water on tap. It can be disconcerting when this switches on at random during the night, though

I switch this settting off, but then the downside is that it takes a good three minutes for warm water to flow when you open a hot tap or turn on the shower.

Also once you are in the shower, you can't then turn the hot water on and off at will, as it will then take a minute or two to get back to stable temperature when you turn it bak on.

If you are glad of the extra space though, you'll probably be happy enough once you know the peculiarities of the combi boiler.

Murmansk

I went from system boiler with cylinder in one house to combi boiler in my current flat.

The cylinder was in the bathroom so I could turn on the hot tap at the sink there and get hot water quite quickly - with the combi I'd have to wait quite a long time, and waste a lot of water, before hot water comes out of the tap, so that's a disadvantage.

Another advantage of the old system was that I could have a power shower with a good flow. I now have a shower connected to my combi and the flow is nothing to write home about, although it's a lot better than an instantaneous electric shower would be.

On balance, I actually preferred my previous system for the above reasons

Ally_E.

We fitted 2019 combi boiler in 3 bed house. It's excellent. Pressure is great and it doesn't take 3 minutes for hot water to come back when switched back on during a shower. It's very seamless and takes 15sec max. We had a tank previously and taking a shower was a struggle with low pressure. Now that we're on mains pressure, washing long hair is so easy and quick.

rach_k

coffeehound wrote: »

I switch this settting off, but then the downside is that it takes a good three minutes for warm water to flow when you open a hot tap or turn on the shower.

Three minutes? Does this vary by how far you are from the boiler? I just tested ours and the kitchen tap is warm after 10 seconds and hot by 20 seconds. The boiler is more or less above it on the first floor so perhaps that's why?

tacpot12

It is likely that you will save money on your heating as the new boiler is likely to be a lot more efficient than the old boiler.

You will also save money on heating hot water for the taps. If the boiler is correctly sized, you should get hot water within 60s, but there is a knack to opening the taps just the right amount to allow you get hot water within 60s, and you will need to open the taps further and further otherwise the water will be too hot.

You will also save money as you can never forget to turn your hot water off when you go away.

shortcrust

I’ve just timed it (is that a bit sad?) and I get warm water in 20 seconds and hot in 25 seconds. Boiler is two floors down. When I turn the shower off for a minute the water doesn’t go cold.

I’d find it really weird to have a hot water tank now. I don’t really like the idea of it anymore.