Hot water upgrade

[Ron_Miles]

Hi All,

I run a pub in Devon and have added some letting rooms. I thought rain showers would be a nice touch but soon found out that our existing cylinder wasn't up to the job so I am in the process of upgrading our hot water system. We currently have a Potterton Kingfisher ii CF 60 system boiler connected to a vented 175l cylinder.

The new set-up will be using, initially the same boiler ( I know the Kingfisher is past it's sell by date but need to spread the cost ), connected to 2 x 300l un-vented cylinders.

The questions I have are:
1, Can I pressurise a Potterton Kingfisher ii CF60 with an expansion vessel
2, Can a Kingfisher ii be used on an un-vented system
3, What would be the best way to control the 2 cylinders and radiators

The cylinders are everflow made by Kingspan and are system cylinders already piped and fitted with 2 way valves, 2 on each cylinder.

Any response would be most appreciated.

Ron.

 

[Plumber90]

First thing, is your water main up to the job?

 

[Dan Robinson]

No you can't pressurise kingfisher.

 

[Ron_Miles]

Hi Plumber90,
Thanks for the reply.
The supply is via 2 15mm rising mains, one to each cylinder ?

 

[Ron_Miles]

Hi Dan,

If I cant preasureise the boiler is it still viable to use it on a preasurided system?

 

[Plumber90]

I would be extremely shocked (extremely) if that is good enough for 2 300litre unvented cylinders. Get your flow rates and pressure checked.

 

[simond]

Dan, I thought the Kingfisher 2 could be pressurised?

If memory serves me you could buy a sealed system version (with an OH interrupter) or convert it with a small add on stat afterwards.

 

[Madrab]

Yup, I have to agree with simon we had an old Potterton Kinger 2 running on a sealed system in the class to practice servicing on, it does need the Overheat Stat kit added though.
That being said, would I want to pressurise a boiler that's live and working in a pub that's at least 17 years old and only ever run on a vented gravity or pumped system.....

 

[muggles]

I think you'd need to buy the manufacturer's original SS kit to do it properly and make it comply, and that'll be obsolete.

OP, your cylinders should really be fed with a 22mm main each rather than a 15mm main. Unless your working pressure is insane I'd expect very poor performance from your cylinders with multiple showers running. Parts of Devon do have very high pressure, but they're few and far between. Your pre-piped cylinders still need to be installed by a G3 registered installer as well, not getting this done will invalidate your insurance and could lead to a very expensive claim if one of them ends up injuring your guests.

I'd consider scrapping the boiler, in a commercial environment you'll soon see a positive return on your investment in terms of gas saving

 

[Madrab]

I think you'd need to buy the manufacturer's original SS kit to do it properly and make it comply, and that'll be obsolete.

nope, still available, is a bit pricey though

http://gasboilerspareparts.com/pott...arts/potterton-overheat-stat-kit-cf-60-907411

Agreed it should be scrapped, less that 65% efficiency etc but the OP is trying to offset initial HW changeover, though I'm sure there could be a better way of doing it. A proper review and a good design drawn up would do for starters methinks..

 

[Ron_Miles]

Hi Guy's,

Thanks for all the feedback and apologies for the bad spelling on my last posting I was in the middle of a pool match. lol

Spoke to Potterton and the boiler is obsolete and spares are no longer available. They stopped making it in 97' so that would make it at least 18 years old, well past it's sell by date.
After a conversation with Punch Taverns, who are the landlords, they have agreed to replace the boiler especially after the latest gas service report condemned it so we are now waiting for them to arrange the replacement.

I know the supply may bit a little under sized but there is no way of increasing it unless we want to start digging up the road. The pub has been here since around 1350, one main is at the rear of the property and is routed under all the terraced houses and the other is at the front of the building which would mean excavation work. The plumber who is doing the installation work has checked the flow and pressure and thinks we should just get away with it by using the 2 mains, 1 on each cylinder. After all, not all of the showers will be used at the same time all the time.

 

[muggles]

Do you know what your static pressure is on the incoming mains? If it's good, you could fit an accumulator to store pressurised cold water ready for delivery to the cylinders. You need to get this right or your guests could end up with cold showers

 

[Ron_Miles]

Hi Andrew,

Not off hand but I will ask my plumber for the details.

 

[flameport]

I thought rain showers would be a nice touch

Unless your intention is to waste vast quantities of water and dramatically increase your water and gas bill, fit normal showers.

The plumber who is doing the installation work has checked the flow and pressure and thinks we should just get away with it by using the 2 mains, 1 on each cylinder. After all, not all of the showers will be used at the same time all the time.

It's rather likely that they will.
Letting rooms = people get up at about the same time, shower at the same time, return from wherever they go in the day at about the same time, etc.

Also consider that water pressure usually varies depending on the time of day, so you need to take multiple measurements. Otherwise 'we should just get away with it' will quickly end up as 'the showers do not work'.

 

[Ron_Miles]

Hi Guy's,

Thanks for all the interest and replies.

The most rooms we will ever be able to let is 3, plus our own so that's a max of 4 showers. If you run at 70% occupancy, and that would only be during the summer season, that's 3 showers at any one time. If the pressure and flow become a problem then we could fit an accumulator as suggested or is there a pump we could incorporate.