New OIL boiler choice

[delberto]

Hi folks,

I’m back again after what must be 5 years or more for some advice / opinion.

My quandary is: Grant Vortex vs Warmflow Agentis??.

The only thread I could see about warmflow was very disparaging in terms of warmflow customer support (or lack of it).

My plumber says it’s up to me but he believes the grant has a better heat exchanger for only approx £100 more. I have read that the newer warmflow claim to save 5L of oil per week vs the competition because of its new heat exchanger which is a lot of money at present (but is that saving when it stops working intermittently me wonders). I’m in sales so don’t buy sales pitches and prefer to ask professionals.

All and any advice welcomed.

Thanks in advance for any help.

Cheers

 

[Exedon]

Definitely the Grant well engineered bit of kit.
We have installed 2 to 3 a week over last 5 years.
Grant have been out to just one in that time.
Warmflow technical is truly horrendous difficult to actually talk to and when 1 minute out of warranty your on your own.
We have also pulled out a number of leaking warmflows way less than ten years old..
Make sure your installer is registered with Grant warranty goes from 2 years to 5 at no cost to you.

 

[muggles]

Hounsfield for a good quality English manufacturer at a decent price, EOGB Sapphire for the best quality and lowest fuel usage, but with a higher up-front cost. Unless you're after a combi, in which case Navien

 

[delberto]

Thanks for the replies gents. I was focusing on grant vs warmflow as they are both very common/popular in Northern Ireland where I now live and therefore servicing shouldn’t be to tricky to sort. Also I can get both very cheap through work.

Also it looks very much like the original firebird non condescending was very much oversized. The house is modern ish 130m2 and the heat loss calculation gives me approx 33k btu for heating (10kw) and and the original boiler was an 80k btu (15/25kw). Even allowing for the domestic hot water I think a 15kw (heat only) boiler would be plenty. Does that sound/look right?

The local plumbers just want to stick the same size back in without doing any heat calcs…….

 

[muggles]

Ah sorry, didn't realise you were over that side of the water. Hounsfield could still be an option for you (and in my opinion far superior to the others) but you'll probably struggle with the EOGB

 

[Exedon]

The Grant would be a 15/21 and come set mid range easily reduced to 15kw when commissioning.

 

[delberto]

The Grant would be a 15/21 and come set mid range easily reduced to 15kw when commissioning.

If it’s set to 18kw ish I would be happy enough as is because I assume it would give faster recovery of the cylinder when it’s cold and there is all round demand.

Thanks Exedon

 

[delberto]

Ah sorry, didn't realise you were over that side of the water. Hounsfield could still be an option for you (and in my opinion far superior to the others) but you'll probably struggle with the EOGB

Cheers muggles,

I have looked up hounsfield previously but no one in my firm has ever dealt with / sold them….. not even our Isle of Man nor North East England division. Never heard of EOGB. I’ll have to Google them.

Thanks for the suggestion

 

[delberto]

Hi gents, just an add on question For the grant experts…

Is there likely to be much efficiency difference between a Grant vortex 15/21 vs a grant vortex 15/26 if both are set to circa 19kw??
the 15/21 ( now discontinued due to range being reduced- but I have 3 at work) claims 93% efficiency at all settings
the 15/25 claims 94-95%!efficiency Depending on setting.
is there a bigger heat exchanger in the 15/26 that gives better efficiency??

at Current oil prices 1-2% saving could be worh £20- £40 a year… and the boilers are only about £20 apart in cost for me…

Thanks In advance

thanks

 

[muggles]

System setup will have more effect on efficiency than the boiler, although if you set a Grant up to fully condense for best efficiency it'll rot out the main heat exchanger in no time

 

[JonathanM]

although if you set a Grant up to fully condense for best efficiency it'll rot out the main heat exchanger in no time

That's interesting! Why is that?

 

[muggles]

That's interesting! Why is that?

Made from mild steel. They need back-end protection to prevent the return water falling below 50ºC and acidic condensation forming on the heat exchanger. Too much condensation on a mild steel heat exchanger = lots of corrosion. This is one of the many places where Hounsfield win, as the return water runs into a stainless heat exchanger

 

[JonathanM]

Made from mild steel. They need back-end protection to prevent the return water falling below 50ºC and acidic condensation forming on the heat exchanger. Too much condensation on a mild steel heat exchanger = lots of corrosion. This is one of the many places where Hounsfield win, as the return water runs into a stainless heat exchanger

That seems a bit of an obvious design flaw. I wonder why they don't make it out of stainless steel.

 

[delberto]

Muggles, how long have you worked for houndsfield

My question is- if both boilers are set up properly by the same tech to the same output would there likely be much difference in efficienc??

 

[muggles]

I haven't, I just believe in installing quality products rather than mass-manufactured stuff with built in design flaws

I suspect you're just looking at different sets of figures though. The 15/21 was most likely rated using the SEDBUK 2005 figure, whereas the 15/26 uses SEDBUK 2009. If you look at the technical data in the manual where both models are listed, you'll see on Page 7 that the 15/21 is rated at 91.2% and the 15/26 at 91.9%, so there's naff-all in it.