New boiler, where to start?

[Kevinthesnipe]

I’ve been told my combi boiler is on borrowed time and I need to start looking for a new one. I don’t really understand the jargon so can anyone help me by telling me what I need to look for.
we have a small 3 bedroom semi detached. Our old one is a Worcester green star 28i junior combi. Family of 2adults 2 kids shower used at least once a day.
TIA

Worcester Bosch is normally a very good brand and very reliable.

Do you know how old is it and what is wrong with it ?

Yes it’s 15 years old it’s had numerous things go wrong with it it was put in by the previous owners.
It loses pressure almost daily having to manually top it up. The plumber who checked it said we’d be better getting a new one. He’s a reliable retired plumber and is happy to install but doesn’t supply himself.

My plumber just made a suggestion (a type of Worcester) and I went with that and then he installed it. I would have had no clue otherwise. Can you ask your plumber what he recommends within the Worcester range?

He says he doesn’t recommend any so he can’t be blamed if they’re rubbish 😬, that’s why I’ve resorted to Mumsnet

Combis are all pretty similar these days. I work in the trade and would recommend vaillant, Worcester or Baxi.

It's pretty rubbish that him as a professional with years of experience and knowledge is refusing to recommend any type of boiler so he "can't be blamed if its rubbish"! What a terrible attitude. So now you as a complete beginner with zero knowledge is having to try and spec a boiler for your house? Bonkers. Can't he give you a choice of three manufacturers that are about the right size for your house, and then you choose - so he can't be blamed!!!

Worcester bosch 4000, 30kw, prob be around the 2.5k mark. Comes with a 10 year parts and labour warranty. Something like that would work.

Sounds like your expansion vessel may have given up, which is an off the wall job, around 0.5k to 1k to rectify.

I went with British Gas, they send an engineer for a free consultation who looks at your pipes and recommends what they think is best. They have finance deals so you can pay the boiler off monthly

First of all, nice as your retired plumber is, you need to ensure he supplies and fits it as otherwise you have much reduced come back. Frankly, perhaps you are better going with a currently working gas engineer that supplies and fits.

Boiler wise, suggest either Worcester or Valiant. We have been using Valiant for the last few years in some rental properties and not one has broken down, but they have a ten year warranty as long as an approved installer (which our lovely local gas man is). They should also advise you on the correct size required. I suggest you go one size up just in case, ie you extend.

However, loosing pressure may not be the boiler. It might be a small leak that you have not noticed if pipes are covered? Also, if replacing the boiler, you may need a power flush through the system. We didn't has hubby ensures they are full of chemicals and also flushes every radiator out when decorating. You may also need a system filter fitting.

Lots to think about so don't cut corners as it may bite you.

FYI, on our own house, when he changed our boiler, the gas usage reduced by 35%". Was staggering

We are in the same situation. We are going to change it in the summer. We are planning for an air heat pump so we get the government grant and increase the house value

Worcester, don't even look at any other makes. But get a different plumber who knows what he's doing. It's his job to recommend the size you need. Getting too small will be a nightmare, and too big is really inefficient. Boilers work best at near full capacity. You need a professional, that's what you're paying for!

Ground source heat pump only if you're in a well-built new build with a decent garden size to house it! They are the future, but almost useless in older buildings.

I agree!

Get several quotes from different recommended boiler specialists.

This. Sounds like he is teeing himself up to be able to walk away from any problem you might have post install by blaming it on the boiler.

Does the retired guy have gas safe registration and will he make sure the install is properly registered ?

@Scottishgirl85 utter rubbish. Worcester are a good boiler, but so are Valiant. For a while Valiant were better but they are very much equally as good.

Agree with getting too small, but not to big. The modern boilers such we have, they can either be turned down to meet the demand required, or more likely they can oscillate down to just provide the gas and heating required. The Vailant is incredibly quiet, as I'm sure the Worcester is. This is what we have used in several properties and not one has failed in 5 years. www.vaillant.co.uk/product-systems/gas-boilers/ecotec-plus-remastered/

Urm, "utter rubbish" is your opinion. Why should the OP buy a boiler bigger than needed? More expensive and capacity that won't be used. It's well known that over-sizing a boiler is not a good idea.
I'm no expert, but we've used several plumbers over the years and all have independently said they now only fit Worcester. I'm sure Valiant are great too, but there must be something in it for various plumbers to say the same thing. Trying to keep things simple for the OP. But basically, she needs a more experienced plumber, no way should she be calculating the size needed...

Why is a pressure vessel so expensive to replace? a brand new one for that model is £100.

Surely it wouldn't cost 500 to 1000 to replace.

I'm asking because i ve a slightly larger Worcester combi 30cdi and its losing pressure over about a week.

I ve been recommended Baxi or Worcester if i want a quieter boiler... but i'm hoping mine can be fixed.

Mainly, the labour cost and location. Boiler has to come of the wall to be replaced

Whenever our boiler has lost pressure it's usually a joint at a radiator leaking a bit, when it has been the boiler there has been signs of wet underneath it.

Everyone suggesting things to do with pressure loss, if the engineer has checked it they will know what's wrong. OP could get a second opinion but I'm assuming it's either the main heat exchanger or the whole boiler is so deteriorated then it's good money after bad to start changing things.
One house we had the first engineer took one look and said too old, new boiler needed, the second opinion said they will try to fix it, one PCB, sensors, pressure switch later, the second one ended up needing to fit a new boiler anyway. The original installation was just a lash up and not installed correctly.

We had a Viessmann boiler-German, 10 year warranty and the Rolls Royce of boilers. They have a stainless steel heat exchanger which means it keeps its efficiency long term. Vailant also have SS. There are several companies which will install for a fixed price and have a range to choose from. Boxt is the best known.

Yes we did discuss Weissman boilers. The stainless steel heat exchanger was a factor in favour of them and Valiant. Worcester didn't have that and was why I was recommended Valiant. That may have changed since the last time we did a boiler change (suggest check). The factor against Viessman for us was availability of parts wasn't at the time quite as easy as Valiant. Obviously things can change quickly so up to date advice from the gas engineer is best. The one I always use fits at least two boilers a week so is really in touch with current quality and part availability, especially because so may customers are leaving British Gas service plans due to the service now being awful, having once been amazing.

@Scottishgirl85 why oversize slightly? All houses have variances, especially old so calculations are always approximate. There is room for errors. Some people like a quicker warm up. Makes a big difference with combi as well. Plus if they extend, it saves another boiler change. The additional cost for us was £80. Well worth it as an insurance and it isn't less efficient per my pp.

In the end the OP needs to check the current quality and part availability but the most important is using an engineer that is currently working and installing boilers all the time. They will know hunch boilers cause them the least hassle in return visits

Thanks for all the advice. Expansion vessel sounds familiar.
I went on boxt and they recommended a few different boilers with wildly different prices and I wasn’t sure what the difference was.

We went for a Baxi, had it 3 years now no issues.