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Jan 3, 2021
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Herts
Member Type
Heating Engineer (Has GSR)
Hi All

First time poster here, I'm hoping you will be able to provide some insight. I'm about to carry out a loft conversion with en-suite on my house (currently a 3-bed semi with 1 family bathroom). At present I have a Vaillant Turbomax Plus 828E combi, and am thinking of replacing this with a stored combi boiler as with converting the loft I don't really have space to go system boiler / unvented cylinder route. I also seem to have pretty good water pressure and flow rate

Measured from my outside tap my water flow / pressure is
20 LPM / 6.5 bar static
18 LPM / 6.5 bar dynamic (with kitchen tap inside running)

I have a 15mm water supply into my property

I considered the Vaillant 938 stored combi as it will be an easier swap, but am concerned there is only 20 litres stored water. I have looked at the Veissmann 111-W stored combi boiler, which has 18 LPM plus a 46 litre stored unvented cylinder (equal to a 150 L unvented cylinder) - however I have no experience with Veissmann boilers

Can anyone please advise if they have any experience with either of these boilers, and which one would be best

Happy to provide any other info that might help

Cheers
 
Very good boilers and will run a few outlets aslong as your main is upto the task

I personally would want the stop tap changing from 15mm to 22mm copper if possible to the boiler
 
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Thanks for the replies

Due to having to fit it in a kitchen cupboard as they both seem to come highly recommended will go for the Vaillant

"I personally would want the stop tap changing from 15mm to 22mm copper if possible to the boiler"

@ShaunCorbs the stop tap is about 2m away form the boiler, if I change this to a 22mm stop and run 22mm pipe up to the boiler then reduce, and also tee off for the cold water for the rest of the house as far away from the boiler as possible will this suffice?

I also wondered as the boiler will be on the Ground Floor in kitchen, will the hot water delivery to the shower & bath be ok up in the new loft bedroom given the pressures / flow rates I have provided?

Thanks for the replies gents it really is appreciated 👍
 
Thanks @ShaunCorbs

Sorry should have been clearer it will not be inside a cupboard, but will be installed in a utility room where an old standard size kitchen cupboard was. As I have to run pipes up the side of the wall the width of the Vaillant at 440mm allows me to do this - the Veissmann at 600mm wide would eat into the adjacent cupboard space with the pipes running up the side

Any thoughts on the distance from ground floor boiler to loft bathroom?

Cheers
 
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