New combi boiler for 3rd floor 2-bed flat

[Sam577]

Hi there,

I want to get a new combi boiler to replace my old conventional boiler, which takes up a lot of room in my flat.

I currently don't have a shower and am desperate to get one, and our hot water runs at very low pressure (kitchen sink is a little more than a dribble).

So the new boiler needs to be powerful enough to heat a two-bed flat and power a moderately powerful shower (would I need a separate pump in addition to the boiler to increase the water pressure?).

I've started looking around on the internet and stores and am finding it a bit of a minefield. I've been advised that Worcester is the best make but the prices I've found everywhere are very high so I'm wondering if anyone can give me advice on what price range and perhaps make would be adequate for my needs (would a new boiler be the only option or are reliable refurbished boilers available?).

I don't want the cheapest thing on the market that will break down very soon but at the same time I don't want to get something that is OTT and exceeds my needs with a very high price tag; after all, I only live in a 2-bed flat, not a 4-bed house.

Any advice would be greatly appreciated as I am a relative novice in such matters and don't want to be ripped off by an unscrupulous plumber like my friend recently was.

Many thanks,
Sam

 

[ajrobb]

I currently don't have a shower and am desperate to get one, and our hot water runs at very low pressure (kitchen sink is a little more than a dribble).

The important thing for a combi boiler is how much flow can you get from your cold tap?

So the new boiler needs to be powerful enough to heat a two-bed flat and power a moderately powerful shower (would I need a separate pump in addition to the boiler to increase the water pressure?).

Most combi boilers in flats have spare heating capacity as their size is more dictated by the hot water. The heating goes off when you run hot water. They run off mains pressure and you cannot pump mains water.

I realise you would like to change current large boiler but have you considered a shower pump with your existing hot water cylinder?

 

[bengasman]

Forget shopping around, it will take you a year to upgrade your knowledge enough to know what exactly is important in your particular case.
Find a good installer, and put your trust in him.

 

[Sam577]

The bath cold water pressure is quite good (the hot water pressure here is moderate – not bad). The kitchen cold water pressure is also pretty good; it’s just the hot water that’s very poor – what can we do to remedy this (I thought it might have something to do with the fact that we live on a 3rd floor flat but since all the other water pressure is fine this doesn’t seem the cause)?

I have been advised by some that conventional boilers are superior in that they are much more reliable, and if everything all works out too expensive, I might just have to do that. The reason we want to change to the less reliable combi is that the flat we live in is not that big and the water tank is huge and is in a cupboard in the passage taking up a lot of valuable storage space. But more relevant in our decision is that there are also tanks in the kitchen that are very unsightly, so we’d rather just have one tank that does it all (there are currently three tanks).

What should I be expecting to spend on a really good, as well as a mid-range, combi boiler?

 

[ChrisR]

Last question first - are you going to fit the boiler?
If not, all you need is to know the installed price. ANy fool can buy a boiler...

Individual poor flow can be due to taps. You do need a competent plumber/installer. If you get a couple/3 quotes you should be better informed, assuming they answer questions!

 

[Sam577]

I'm not going to fit the boiler but I want to be a little informed of the quality of the choices I am given and what their prices should be

 

[D_Hailsham]

I only live in a 2-bed flat

If you are thinking of a combi, you need to check the incoming cold water flow rate at the tap in the kitchen as this will be the flow rate through the boiler for hot water. Use a bucket with litre markings and a watch.

Work out the flow in litres per minute and multiply this by 2.5. This will give you the size boiler for hot water. Select the nearest size larger.

Although the hot water requirement determines the size of the boiler, you should also work out the central heating requirement of the flat. You do this by using the Boiler Size Calculator.

When looking at boiler specs you will see that it quotes a range for the heating output, e.g 6kw to 18kW. The higher limit will be well above your heating requirement as you have a combi boiler. But you should make sure that the lower limit is as far below your calculated requirement as possible. Remeha Avanta boilers are very good for this.

 

[Sam577]

Thank you all. I will find three plumbers or more and get quotes.

Are there any makes/models I should particularly avoid, or a minimum threshold I should expect to pay for a decent one?

Thanks again.

 

[simsgas]

i would go for a boiler with at least five years warranty,so that gives you no unexpected repairs and peace of mind after paying out for a new system,just fitted the new ideal logic plus combi/5yrs warranty good looking and easy to control.

 

[bengasman]

Are there any makes/models I should particularly avoid, or a minimum threshold I should expect to pay for a decent one?

.

Ideal is no doubt the bottom of the lot when it comes to appreciation of installers when it comes to quality of the product, and Vailant when it comes to customer service.

 

[vulcancontinental]

Other thing to think of is that you're on the third floor.

Does your current boiler flue go straight out the wall behind the boiler or onto a chimney? If the latter get a boiler with a flue that can be fitted from the inside, if the former the boiler possibly has an old 14" x 12" boiler flue hole that has got to be made good. It's got to be done three stories up which can be a problem in itself if over a roadway, footpath or outbuildings.

If you're in a posh block of flats the other residents will not want to see a old hole patched up from the inside. In any area I wouldn't want to see an old hole filled up from the inside.

Your hot water flow if you convert to a combi will be similar to your cold water flow unless you have a fantastically high cold water pressure at the kitchen sink.

Pumping the existing hot supplies might be attractive and simpler - certainly cheaper and probably more reliable.

Worcester boilers are far from perfect, no boiler is perfect.

Don't ask about boilers and systems, ask everywhere you can, work, friends, social groups etc for recommendations of installers who have done something well and are reliable; it's all about trusting the man who puts it in to give good advice and then do a good job.

Are you in a flat you want to stay in for many years?
How desperate are you for the space? (£1500 - £3000 desperate?)
What boiler do you have at the moment?
How old is it and the rest of the system?
How old are the flats and how salubrious?
Have you got a foam jacket on the hot water cylinder?
I assume current running costs are manageable.

 

[bengasman]

...Although the hot water requirement determines the size of the boiler, you should also work out the central heating requirement of the flat....

Feel free to ignore the advice of this amateur; he is not, and never has been a pro.
That is why he often gets it only half right. There is no need whatsoever to calculate what the heating requirements are when you install a combi in a flat. Total tosh.