Heat only boiler to combi upgrade

[ash121]

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

 

[Riley]

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

 

[quality]

I would advise to up grade your existing system with a new heat only boiler and un-vented cylinder. I dont see a conversion to a combi as an upgrade from a traditional system

 

[Scott_D]

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.

 

[Millsy 82]

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?

 

[Harvest Fields]

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?

I agree with the above mate. I don’t like the idea of a combi in a 4 bed.

 

[Brambles]

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

 

[ash121]

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?

 

[Riley]

Is your mate giving you the boiler? Who is doing the install that is way too cheap

 

[ash121]

Is your mate giving you the boiler? Who is doing the install that is way too cheap

He is selling it to me at £750 🙂 i have a plumber doing the work he is gas safe registered

 

[Brambles]

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

 

[ShaunCorbs]

Too cheap I can’t even buy the vogue for that

As for install how long has he said it will take ?

 

[Brambles]

If you have the boiler and the plumber all lined up, why are you asking these questions ?

 

[ash121]

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?

 

[Stu-B]

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

 

[Riley]

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

 

[ash121]

Anyone based in Coventry? To provide a quote to upgrade current system

 

[Harvest Fields]

Anyone based in Coventry? To provide a quote to upgrade current system

Thought you said you had a bloke?

 

[Riley]

I’m assuming he’s either a combi slinger or this is DIY

 

[ash121]

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!

 

[ash121]

Thought you said you had a bloke?

I have but thats for a combi not to upgrade the current setup

 

[Harvest Fields]

I have but thats for a combi not to upgrade the current setup

He should be able to do that also.

 

[ash121]

He should be able to do that also.

He was insistent on a combi change!

 

[Riley]

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]

I couldn't agree more, hence why i asked anyone from Coventry on here who would look to provide a quote?

 

[Scott_D]

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!

More than double your quote

 

[Millsy 82]

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!

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.

 

[ash121]

I'm going to get a few more quotes to upgrade the current setup, having second thoughts whether fitting a combi is the right thing to do 🙁

 

[Riley]

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)

 

[ash121]

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)

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?

 

[Riley]

The boiler can be range rated accordingly. But let’s not kid ourselves you are getting it for the hot water supply correct? You don’t know that your incoming mains pressure and flow are adequate to supply the boiler with what it needs. The thing with that is if it is adequate then why would you want a drop-in flow every time someone opens up a second outlet which is exactly what will happen with a combi boiler. This is where these high kilowattage combi boilers are a difficult decision. You would get one pretty good shower to outlets open is never going to happen

 

[ash121]

The boiler can be range rated accordingly. But let’s not kid ourselves you are getting it for the hot water supply correct? You don’t know that your incoming mains pressure and flow are adequate to supply the boiler with what it needs. The thing with that is if it is adequate then why would you want a drop-in flow every time someone opens up a second outlet which is exactly what will happen with a combi boiler. This is where these high kilowattage combi boilers are a difficult decision. You would get one pretty good shower to outlets open is never going to happen

Yep, definitely for the hot water supply, rather than the heating, in our previous house, we had a combi very rarely the bath/shower and kitchen taps would be used at the same time, this is the only time i recall a drop in water pressure. In light of our circumstances that's why i think a combi will also be suitable

 

[Millsy 82]

I agree with the above mate. I don’t like the idea of a combi in a 4 bed.

Not so much a combi in a 4 bed as I believe there are times it's acceptable to install a combi in a house that size. I know I'm in the minority on thinking that as we've been down that conversation before a couple of times.

Reason I dont really like them is because people think they are suitable for running 2 bathrooms at the same time. If you have 2 bathrooms and want to use them at the same time then get an unvented if you dont want to use them both at the same time then get a 30-35kw boiler.

 

[Riley]

I agree with the sentiment you are talking in your current situation but I don’t understand why you don’t future proof in case your family grows or you take on a lodger that sort of thing?? The combi boiler will not be sufficient for using both bathrooms or likely even the hot tap in the kitchen and the shower

 

[ash121]

Not so much a combi in a 4 bed as I believe there are times it's acceptable to install a combi in a house that size. I know I'm in the minority on thinking that as we've been down that conversation before a couple of times.

Reason I dont really like them is because people think they are suitable for running 2 bathrooms at the same time. If you have 2 bathrooms and want to use them at the same time then get an unvented if you dont want to use them both at the same time then get a 30-35kw boiler.

Its one bath and a separate electric shower in another room but definitely won't be used at the same time. Maybe on the odd rare occasion.

30-35kw vs going for the 40kw will there be any advantages?

 

[Riley]

I know I’m playing devil‘s advocate but what’s the point in buying a house with two bathrooms if you’re never going to use them both you might as well have bought somewhere smaller, I know that’s not the point in question but you seem to be trying to use every argument to justify a combi boiler when we are giving you the honest opinion that it’s not the best answer for your property. I realise your mate is giving you a good deal on it but don’t undersell your home for the sake of saving a few quid as you may find you’ll be ripping it all out and changing it in the future

 

[ash121]

I know I’m playing devil‘s advocate but what’s the point in buying a house with two bathrooms if you’re never going to use them both you might as well have bought somewhere smaller, I know that’s not the point in question but you seem to be trying to use every argument to justify a combi boiler when we are giving you the honest opinion that it’s not the best answer for your property. I realise your mate is giving you a good deal on it but don’t undersell your home for the sake of saving a few quid as you may find you’ll be ripping it all out and changing it in the future

I totally see your point, in the future we are planning on converting the loft so wouldn't want any tanks, i presume there are tanks in the loft? Is there a solution/setup where i just have the cylinder and boiler?

 

[Riley]

Yes that’s exactly the one we have been telling you about 😉

 

[Riley]

Seal your heating system - f&e tank goes
Install an unvented cylinder - cold water storage tank goes

 

[ash121]

Seal your heating system - f&e tank goes
Install an unvented cylinder - cold water storage tank goes

Ah ok, can you explain further when you say seal the heating system, what's needed to do that?

So i can get rid of both tanks in the loft? And get an unvented cylinder?

Can you recommend an unvented cylinder and boiler?

Is there alot of alterations to the pipe work to do this? Any idea of costs?

What's the maintenance compared to a combi?

 

[Millsy 82]

Its one bath and a separate electric shower in another room but definitely won't be used at the same time. Maybe on the odd rare occasion.

30-35kw vs going for the 40kw will there be any advantages?

In my opinion unless you are going to be trying to run 2 taps at a time most people wouldnt notice they are getting 13/14ltrs a min compared to 16. Yes your bath may take longer to run by 2/3 minutes but every time you use a basin etc you wont be using it to it's full potential.

As you have said you are looking to extend my advice would be to go down the unvented cylinder route. Gets rid of you tanks in the loft gives you the best hot water.

 

[ash121]

Im swaying to go with an unvented cylinder, this is new territory for me? I didn't know i could remove the tanks in the loft

Can you recommend a cylinder? What size do i go for? What brand? Whats the difference between direct and indirect?

 

[Millsy 82]

Im swaying to go with an unvented cylinder, this is new territory for me? I didn't know i could remove the tanks in the loft

Can you recommend a cylinder? What size do i go for? What brand? Whats the difference between direct and indirect?

Get a few quotes and they will advise you. You need someone who holds qualifications in both gas boilers and unvented cylinders.

 

[Harvest Fields]

Get a few quotes and they will advise you. You need someone who holds qualifications in both gas boilers and unvented cylinders.

As above. Good words spoken.

 

[Riley]

Do your research as well how an unvented cylinder works Unvented Cylinders explained

 

[ash121]

Guys hate to say this, but appreciate all the advice, going with the unvented option will cost me considerably more, so will be going with the combi.

Just read this review on screwfix on the vogue c32 which is reassuring

Ive had this boiler installed just about 3 months now and couldnt be happier with it.
Its extremely capable and very functional considering the cheaper price tag it comes with.
It looks very modern which is exactly what we wanted and is very user friendly with its colour display and easy controls.
It has many useful energy saving functions like its ability to modulate higher and have a pre-heat function to always keep the water hot for your demands, saving on wasted water.
If installed with the approved filter aswell you get an extended warranty of 10 years which is really good. Obviously you have to have it serviced every year to maintain it aswell.
We have recently installed a new bathroom suite and built a wetroom both with VERY high flow demanding taps and shower heads.
The boiler is more than comfortable in keeping up with both flow demand and evenly maintaining water temperature.
Overall i would say this is a great boiler with many perks and is fit for any 3/4 bed house with 1 or 2 bathrooms. "

 

[Riley]

But it won’t be capable if your mains isn’t up to it. And I hate to say it but that last sentence about serving a house with 2 bathrooms makes me think it’s someone from Ideal that’s posted it.

 

[Riley]

Actually re-reading it I’d say definitely someone selling them has written that

 

[Harvest Fields]

As above the last sentence sounds like it written by someone that isn’t a genuine home owner looking to upgrade a system.

 

[ash121]

Is there any way i can test the mains flow myself?

 

[Brambles]

Yes, buy a flow (weir) gauge from screwfix - about £15

You could write a review too after you have used it!

 

[ash121]

Great, so if its over 16 litres per min go for the combi?

 

[Riley]

Get a container you know he volume of and fill it from an outside tap ideally and time it.

 

[Riley]

Ha ha buddy you are on a professional/diy plumbing site I don’t think any of the guys here are going to say that the combi is the way to go

 

[Brambles]

I would say that to get the full dhw output at the boiler (40kw) you would probly need nearer 19 litres/minute at the mains outlet. If you are getting a lower flow look at the 32kw version or consider adding a pumped accumulator

 

[Millsy 82]

I'm smelling DIY gas work about to take place.

1st of all a mate was going to sell him a 40kw boiler cheaper than anyone else could ever get one now looking at screwfix to buy a boiler.

Had a person lined up to convert from cylinder to combi for £600!

I'm out 😎

 

[ash121]

Lol i was looking for reviews on the boiler in question no harm in doing that! How have you come to that conclusion by me just posting a review that i found on screwfix if it was DIY i wouldn't have raised the point!

Thanks for your input thus far

 

[Drewy]

A storage combi is a perfect compromise. Problem is it wouldn’t fit in the same position the existing boiler is fitted.

 

[ash121]

A storage combi is a perfect compromise. Problem is it wouldn’t fit in the same position the existing boiler is fitted.

Could it be located elsewhere?

 

[Riley]

Yes. All of these things are relocatable in 95% of cases. Your limit is your budget.

 

[ash121]

Yes. All of these things are relocatable in 95% of cases. Your limit is your budget.

Apologies i thought it was something separate that would connect to the boiler🙄

 

[Riley]

Apologies i thought it was something separate that would connect to the boiler🙄

No it’s one huge boiler with a small water store built into it

 

[Riley]

No it’s one huge boiler with a small water store built into it

Well I say huge it’s not but it’s a damn site bigger than a normal boiler

 

[ash121]

Well I say huge it’s not but it’s a damn site bigger than a normal boiler

Haha no worries, thanks for all your help and advice and others, will buy a flow gauge and report back on the flow rate

 

[ShaunCorbs]

Easy way to test how long to fill a 1l bottle for 16lpm your looking for around 4 seconds maximum