advise needed on plumbing \ heating system

[soul2soul]

Need some advice please on a plumbing \ heating solution for a 1930’s 3 –Bed Semi in South West London. Currently have one bathroom with a mixer shower in the bath but plan to go into the loft & have a shower & maybe bath up there as well at some point in the future. Water pressure in the bathroom is below average at the moment & I long to have a powerful shower.


The current system is a conventional one consisting of the following

• Potterton Suprima 60 HE Conventional Condensing Boiler
• 12” Tall By 58” tall hot water Cylinder
• Water Tanks in Loft
• 15mm Lead water supply into property
• new stelrad radiators all round.


Proposed system is

To renew water mains to property (35mm from mains to stopcock, 25mm from stopcock to property, 15mm to bathroom.) This includes going across a driveway. (£2200). Been told that needs to be done as it is the basis for a good system as well as the lead being prone to corrosion either now or in the new future.


Then to either convert to a high flow rate combi boiler at the same time (additional £2000)

Or to get a custom made fast recovery hot water tank 12” wide by 79” tall (£800 including fitting) as there is no space to go wider due to window. Then have the option of going to a megaflow or changing the system to a combi boiler if \ when we do the loft.

I am sceptical about going the combi route as I have reservations about them serving two bathrooms. My plumber prefers the combi option as he thinks that the mega flow will be overkill for a property of this size. I am aware that if we go the custom cylinder route then we will have to rip this out if we do the loft but that may not be for a few years yet.


Please advise as I am going spare over what to do & want it resolved this side of Xmas.

 

[Agile]

A major factor in the choice of a combi or cylinder is how many people live there but you have not disclosed that.

A combi will only run ONE out fully at a time.

Thats no problem for one person, no problem for two people if one makes the tea while the other showers. If you have two teenage daughters then forget it!

Tony

 

[soul2soul]

Sorry forgot to add that - two adults at the moment. But there will be kids in the near future.

So my plumber is wrong about the high flow combi's being able to cope with two showers at the same time? If so it looks like a custom tank for now then a Megaflow if / when we do the loft?

Regards,

Zak

 

[simond]

We have many satisfied customers running a fast flow combi, such as the Vaillant 937, Bosch Hiflow 440, and Viessmann 333 (your budget wouldn't get near the last option).

Your 12x60 cylinder would suffer from water stratification (not the same temp all the way up) and the stored water content would very quickly deplete given the usage justifications you are giving for not having a combi.

Furthermore the custom cylinder will need negative pressure pumps in the loft conversion, potentially waking up the family if it is used out of hours.

So, if I were you I'd listen to the plumber or get a 2nd on site opinion. But if you do go down the combi route it is the flow rate of water that is key. If you can't be confident of getting 25 litres per minute minimum you are wasting your time.

NB: If you have room, have you considered getting an ACV sideways unvented hot cylinder in the eaves, which is about as fast recovery as you can buy......

 

[soul2soul]

thanks for your comments so far.

So if I have undertood correctly the custom tank will create more problems than it solves? I have looked at the Bosch HiFlow but this would mean relocating the bolier to the understairs cupboard (it's currently in the kitchen about 4 metres away from the cupboard) so not sure how much cost this would add to the job. Assume this has a higher flow rate than the Valient?

Cannot find any info online on the sideways unvented cylinders are these similar to megaflows but laid horizontally?

Would love to get a 2nd quote \ opinion so any one based near Wimbledon \ Raynes Park please fell free to contact me but remember the job needs doing this side of xmas.

Regards,

Zak