New boiler - combi or unvented, cylinder size and make and model

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Our boiler has stopped working and I've had 2 quotes for a new one but they're both recommending different options.

We have a 3 bed house and there are 5 of us.
We currently have a 900x400 cylinder, tank and boiler.

Water pressure is 14/15 litres per minute.

1 bathroom, currently with electric shower but will be replaced with thermostatic when we upgrade and downstairs WC.

One engineer is recommending unvented system with 120l tank. I'm concerned with this option as Google is telling me I need atleast 150l + . And with 3 kids who like baths and showers and will all soon be teenagers I don't want to be waiting for it to reheat. This guy is set against combi saying they will start to break down after the years and have max 10 year life span. Plus side is we will have an immersion but cost to put is in higher.

Combi is cheaper, we only have one bathroom but I'm concerned that it'll take ages to run a bath in winter when the water temp will be starting off lower. But I like the idea of keeping some cupboard space and having instant endless hot water.

Unvented is recommending the brand Joule mid range ? I have never heard of them and on going can only find cylinders and no boilers

Other guy is recommending valiant.

Also has anyone got experience with condensate pumps? Are they really noisy?
One us saying to go up into loft and go into soil pipe other is saying to go straight out and have a soakaway dug?

Any advice gladly welcome because at this point I am very confused.

Do you have feeder tanks in the loft?
We just did a like for like change of boiler with ours so we kept the tanks and water cylinder. We got a Vaillant condensing boiler

The water tank currently sits above the boiler and cylinder in a very large airing cupboard.

The new boiler will be in the smaller cupboard next to it, as the airing cupboard will house the new walk in shower.

An unvented cylinder is more often around 200 litres if you have room for it.

However, a bath holds around 100 litres, and a modern boiler can reheat it in about half an hour, so is sufficient if you only have one bathroom. If you have two people trying to run baths or showers at the same time or within minutes, you would need the larger cylinder.

If you have an unvented cylinder you will not need a cold water tank.

If you have a cylinder of any type, then of course have an immersion heater (or two) in it so you can still have hot water on the infrequent ocasions when the boiler is out of action.

A combi boiler will not have this facility, and I also agree that they have more to go wrong, and may well be more expensive to maintain, and possibly a shorter life than a simpler boiler.

condensate pumps:

I don't know why one is needed in your case. It is usual, preferable, and simpler, to have the condensate waste pipe connected to a convenient nearby wastepipe or drain, such as the one for the bathroom or kitchen sink. This is much better than running one outdoors where it can freeze.

We went for invented. Can't remember tank size. I had concerns about the reheating as our bath is bigger than the tank. I needn't have worried. The invented cylinder is a separate tank to one which heats- unlike old school immersion heaters id been picturing. The heating cylinder heats some like 40 litres per minute, so I'm pouring out less volume than I can heat, so don't need to worry.

Biggest benefit is one of is can have a shower whilst the other runs the hot tap with minimal pact.

*minimal impact. On shower pressure I mean (boiler driven thermostatic with huge head).

*unvented even. Sorry!

Our Worcester combo is a thing of beauty (just installed after our other started to die at 20 years old). Wouldn't have anything else.

We have unvented with a 250L joules tank and it’s been great. No problems at all. We had it installed in the airing cupboard and the water tanks removed from the loft.

And we have a baxi boiler not a joule one. We just have the joule tank

Your water pressure is huge. I'll go for a big combi boiler that can take 2 showers at the same time and save the space for the tank.

@chukwe

Your water pressure is huge. I'll go for a big combi boiler that can take 2 showers at the same time and save the space for the tank.

I didn't think our water pressure was huge? I thought the minimum was you needed?

@PigletJohn

condensate pumps:

I don't know why one is needed in your case. It is usual, preferable, and simpler, to have the condensate waste pipe connected to a convenient nearby wastepipe or drain, such as the one for the bathroom or kitchen sink. This is much better than running one outdoors where it can freeze.

Unfortunately we don't have a handy nearby waste pipe. They can only join the waste pipe j the loft but the boiler will be in an airing cupboard. Only way to join it otherwise would be to rip our bathroom out.

Callmeadoctor Just wondering how you found a suitable installer? Our WB is dying too, and think easier to replace but finding it hard to work out who to install it.

We literally googled boiler installers in our area, then went off the reviews from customers. Our company was also one that the local council use for disability installation too.

They did a superb job (worcester too, like callmeadoctor)

Iloveaglassoffizzy been trying that, two never quoted, two quoted but had long lists things they weren't responsible for/things they might charge extra for, seemed a bit too risky. Waiting on another installer but he was supposed to do a fix on the old boiler, said what he was doing would definitely do the trick and it didn't. Thinking of trying BOXT on the basis it's no more risky than unknown local installers and at least there's a company behind it. But might check out local council installers too, hadn't thought of that.

You can look on the manufacturer's website to see if they have a register of "approved installers."

Beware of advertising websites where traders pay to be listed, even if the website masquerades as a trusted or recommended source.

In some cases unfavourable reviews are suppressed, and maybe some are written by the trader, family and buddies.