Heat only boiler to combi upgrade

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Heat only boiler to combi upgrade

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ash121

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Hi all,

Looking for some advice, moved into a detached house which has 4 bedrooms, 1 bath and an electric shower, 14 rads in total.

The current setup which i have no idea how it works, has a heat only boiler which looks quite old and a cylinder in the bedroom cupboard, pics attached

I've had a few quotes, and it has been suggested to rip out the old system and fit an ideal vogue c40 combi boiler which has a flow rate of 16.4 Ltr/min

Will this boiler be more than adequate to do the job? Or is it too big for the house?

I would appreciate your advice

Cheers
 

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It’ll do the job. Depends what you want though. Have you discussed your requirements with your installer?? Vogue wouldn’t be my choice but that’s a different story
 
Yes it should be up to the job providing you have enough incoming flow and pressure to give you 16lpm.
I think the vogue is a good boiler.
 
I'm not a big fan of 40kw combis. If you have the requirements for a 40kw combi then get an unvented.

Is it you have 1 bathroom and 1 shower room?
 
Choices,choices,choices...

In the end it will come down to your personal preference (and if you need the space where the current hot water tank is).

With respect to a large combination boiler, they are only as good as the dynamic cold water flow that feeds it. Be absolutely sure that you have an incoming dynamic water pressure at the point of entry into the boiler that can achieve the boiler output. Whilst you indicate that your boiler is 16 litres/min, that could equate to needing around 18 litres/min at the meter. There is little point in having a combi larger than the cold water feed flow - they should always be sized to your actual flow rates.

My personal preference would be system unvented, but it would be more expensive. However you would end up with a smaller boiler and, in my view, better control of your hot water.

Having said that a properly specified Combi would probably work well for you.

In my area, I rarely come across 40kw + combi boilers that are running at anywhere near their design capacity for hot water
 
Yep, its one bath and a separate electric shower

The gas pipe is approx 5 to 7 metres away, my previous house had 22mm gas pipe ive been told the gas pipe will need to be upgraded to 28mm. There is no gas fire in the new house but there is a gas cooker

Space is not an issue re costs i'm getting the boiler at a really good price as my friend owns a plumbers merchant. In total its costing me £1350 including the install

If i were to upgrade the current system, what would this likely cost?
 
The 28mm minimum is correct for that length.

Water flow rates are absolutely key - no point paying for a larger gas line, if you cannot use the gas! You CH load is probably only 50 to 60 % of your proposed boiler capacity.

For costs, it depends where you are located and the complexity of the job.

Best to draft up a specification and then get three comparative quotes
 
Too cheap I can’t even buy the vogue for that

As for install how long has he said it will take ?
 
2 to 3 days I've been told it'll take

I haven't actually purchased the boiler yet, looking for opinions as to whether i should convert to combi or upgrade/replace the current setup and whether the vogue is the right boiler to go for

Read this about the vogue, Up to 7:1 modulation, what does this mean?
 
I’d be more inclined to stay with boiler/cylinder set up and maybe going to an unvented cylinder as long as you’ve got adequate pressure/flow rate, see how much your mate at the merchants can get a 18kw boiler and a 300l cylinder for
 
It will cost you more short-term with an unvented cylinder however the results assuming that your mains is up to it will be vastly better than a combi
 
In the nicest way that just means he’s a Combi slinger and probably doesn’t have the skill set to give you the work you require. Anybody that won’t entertain any other sort of system I would steer clear of
 
ash121 said:
Definitely gas registered, how much would you have expected it to cost to convert to combi? Labour and parts?

I hope no corners are cut!
Click to expand...

I've priced a few bbu out combi in airing cupboard and they have been coming in at around £2600-3000 with a 30kw combi.

If they are charging you £600 labour and materials then my guess is it's a cash job and they will be stealing from their bosses.
 
Your initial proposal is probably tolerable should you stick with the electric shower. However it’s overkill size wise fitting a boiler like that when your heat requirement is probably less than half the boilers capability plus you will get a much more satisfying shower or showers should you go down that route from an unvented cylinder (supplies allowing)
 
Riley said:
Your initial proposal is probably tolerable should you stick with the electric shower. However it’s overkill size wise fitting a boiler like that when your heat requirement is probably less than half the boilers capability plus you will get a much more satisfying shower or showers should you go down that route from an unvented cylinder (supplies allowing)
Click to expand...

Although the boiler is oversized from a heating perspective, would it not modulate down to adjust?

The vogue has Up to 7:1 modulation, what does this mean?
 
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