Do we want a combo boiler ?

[OneFrenchEgg]

Currently gravity fed system, 15 years old. Coming out this week to give an idea (boiler people).

Biggest issue is heating the water for four hours ish a day (am and pm) and then adults on shift/lazy/going out not having water because they are showering at the wrong time or after everyone else.

Due to CoL, and disability, five adults and one teen living here.

Radiators all fine, some have been updated more recently than others but all within the last five years.

We've literally just had this shower fitted. We had a power hungry electric shower before that you had to run around underneath to get wet. We have a combi boiler and we had the HP version of this shower to get the power. I worked for a plumbing company and this is the shower they always recommend. It's fab, and it's thermostatic so it doesn't matter if someone else turns on a tap.

Also, we have a green house type heater in the cupboard where the tank was which is low wattage and keeps the towels, etc, aired.

@OneFrenchEgg If you only have one bathroom, a Combi boiler will be absolutely fine and much better than what you have now. You will never run out of hot water again.

Some of the comments on this thread must be based on very outdated boilers. Good modern boilers that have been chosen (or recommended) for the size of house that they are going into will have none of those issues. They have a pre-heat setting so that you are never waiting ages for hot water to come through and you can set the water temperature according to your preferences.

I think you mean the hot water cylinder not boiler.

If you have a system boiler/hot water cylinder you just turn it on half an hour before you need the water. By keeping the water heating switched on it tops up the temperature when it falls below a certain point - you don't need to wait.

Millions of families in the UK have these systems and manage it just fine, so it's not exactly rocket science. In fact I would say it is the best system to have, especially if you use a lot of hot water.

Oh that's a really good idea thank you

That shouldn't happen and can be sorted by a plumber.

We've had combi boilers for past 30 years and I wouldn't change it. Never run out of hot water and it's instant. And we don't have a cumbersome tank which is just a waste of space - and time taken to heat up.

Ok just under £400 to change to combi for the shower - and it's got an app! Who knew 😀

I shower while the washing/dishwasher (sometimes both) are on, on occasion. It doesn’t affect the warmth of my com I heated shower. With only one bathroom, therefore only one shower on at a time, I don’t think the OP will have an issue.

No idea about your fancy shower but I guess we bought a brilliant electric one from B&Q many years ago. Less than £80 and both DD take hour long showers several times a week and our monthly electric bill is approx £120 (with tumble dryer in winter, etc). Perhaps I'd better not move!

It would be great if you can post an update at at later point, whatever you choose.

Doesn't in our house. We quite often have the dishwasher and washing machine on and the water stays very hot.

We're in a 2-bedroom flat and have had a combi for years. Because the boiler heats the water as it comes in from the mains, the faster you run your bath, the cooler the incoming water gets - you need to find the sweet spot with the tap. So your bath takes longer to fill but you can have as many as you like as you're not relying on a tank-full of water. It also takes a few seconds of running a hot tap before the water comes through hot. We've never noticed a drop in temperature if hot water is being used elsewhere. As to drying towels, we've got a tall, wall-hung, heated towel rack that does the trick.

God, I miss my combi boiler. Hot water on demand. Not a bath family.

Moved to a house with multiple bathrooms and we actually run out of hot water. In 2024. Ridiculous indeed!

Hi - we have someone coming out Friday to run through options . I will update definitely. So far my questions are:

Effect of dishwasher / washing machine if any
Temperature of water (needs to be HOT)
Water pressure
Can they change the processor of the shower if we supply it?
Which is better, combi or gravity feed for us?

Not interested in other fuel sources so it's traditional gravity fed or combi .

No. Its a fucking bastard pain in the arse. Brand new boiler in a new build and I've had 4 months out of 12 with no or intermittent heating and hot water. I have to top up the pressure myself to get it back on and so far it's been the heat pump, heating plate and now the expansion valve. No water pressure from hot tap either. Takes half an hour to fill a bath. All I get is shrugs and 'it's a combi boiler this is what they're like.' It's infuriating.

The person you need is @pigletjohn.

(Much more capable on plumbing issues than Nanny McPhee) 😂

That’s another advantage of the gravity fed systems, if the boiler packs up you can still heat the water using the immersion heater, it’s only the heating which is affected.

Oh wow. That sounds awful. What brand is it?

Combis are much better. When we had a tank you could only have a couple of baths or showers and then the water ran cold, which is useless with a family. With a large family like yours and one bathroom, everyone can have a morning shower with a combi.

I have a combi boiler.
Whatever you do, if you live in a flat that involves a downstairs entrance, don't put it in that area. It takes FOREVER for the hot water to trundle its snail arse upstairs.

Ours reheats really quickly again, it never runs out so long as it is switched on for the duration of people showering / bathing.

The problem we have is it's on say 6-8am for the early starter and the school kid.

Then the shift worker and late riser end up putting it back on at about 2pm (or whenever).
Then it's on 5-8pm to cover my disabled daughter having a bath and another one having a shower.
If anyone goes to the gym/gets back late/is going out it interferes with the evening water.
So hot water on demand would be brilliant

A modern boiler can heat a modern cylinder in 20 minutes. Once it is hot, the boiler does not use gas until it needs heating again.

There is a slight advantage in using the timer to prevent the boiler running for short periods to reheat every time someone washes up (this is what combis always do, and is inefficient) but there is no need to run out of hot water.

Modern installation often have rather large cylinders so they hold enough for a couple of baths and a shower.

I agree, we have ours on for hours every day and it only heats what you use because the cylinder keeps the rest hot. Our gas bill drops to very little in summer when the heating is off (we cook with electricity so the boiler is the only use of gas). If you had a programmable controller you could have it on for a couple of hours every morning, lunchtime and evening and never run out of hot water. Plus as mentioned upthread an immersion heater as emergency backup.

Beware of people saying their brand-new combi is better than their worn-out 25-year old cast-iron conventional boiler was.

Compare two modern boilers.

Do you prefer gravity fed systems to combi? Many many years ago I had a housemate who was a plumber who said this but I assumed things had changed.