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I have been looking into purchasing an unvented hot water cylinder system for when we have our loft conversion (we will have a 3rd bathroom), which is starting next week.

Due to storage constraints for the location of the cylinder, the plumbers that have viewed the property have advised either to put the cylinder (250l-300l) in the eves of the loft (which would cause a lot of disruption to the rest of the house) or in the cellar (far less disruption).

While I have been looking online at various cylinders, I have come across some forums stating that Horizontal cylinder are not as good as vertical and should be avoided unless no other choice.
One thing I could not find in addition was the exact reasons for this?
We do have a choice of having a vertical option but it would mean having two 150l cylinders side by side, which is not ideal due to the costs and setup.

We are deciding to stick with out combi boiler (33kw) and have it modified so it runs as a heat only boiler - apparently we need to have one tap that is used regularly for this setup to work (something to do with the diverter valve working properly?).

The plumber we are thinking of going with has advised we would still need to run a 22ml pipe from the cellar to the new third bathroom, where as others have said they can feed of existing heating pipes from the first floor.

Any one have any experience of setting up an horizontal unvented cylinder, especially in the cellar?
The head height we have is 1.5m and width 2m

Thank you
 
Fitted several horizontals with no problems. With your 1.5m x 2m space you will probably want to avoid cylinders with the immersion in the end as you won’t be able to remove. The other thing to consider is getting the safety devices either out of the cellar or to a drain.
Why do you need to run a 22mm feed to the new bathroom is this for hot water or central heating?? Also you will probably need a minimum 22mm cold feed to the cylinder
 
Fitted several horizontals with no problems. With your 1.5m x 2m space you will probably want to avoid cylinders with the immersion in the end as you won’t be able to remove. The other thing to consider is getting the safety devices either out of the cellar or to a drain.
Why do you need to run a 22mm feed to the new bathroom is this for hot water or central heating?? Also you will probably need a minimum 22mm cold feed to the cylinder
Thank you for your response.
We are thinking of an indirect cylinder therefore no immersion (am I correct?)
So we have 40cm wide, by 50cm heigh and 5m long ditch in the cellar (previous owners dug for head height) that we have been advised can use for discharge. It currently has a pump in there as they dug into the water table!).

He wants the 22mm feed for both hot water and central heating.

We also have a bleu 25mm pipe running into the property from the road.
 
INdirect will still have an immersion option as back up I believe. I’ve never seen one without.

Who advised a trench would be adequate for the safety devices? Does it run anywhere?? If your cylinder starts to pass at the safety devices at mains pressure that could flood very quickly if it’s not an appropriate drain. Pictures might help

I would say 22mm is a must to the water and central heating. If you’re looking at using hot water over a number of floors then a secondary return would avoid water wastage.
 
INdirect will still have an immersion option as back up I believe. I’ve never seen one without.

Who advised a trench would be adequate for the safety devices? Does it run anywhere?? If your cylinder starts to pass at the safety devices at mains pressure that could flood very quickly if it’s not an appropriate drain. Pictures might help

I would say 22mm is a must to the water and central heating. If you’re looking at using hot water over a number of floors then a secondary return would avoid water wastage.
The trench has a pump in it however only one plumber had reservations about it.
We have the option of putting a vertical cylinder in the hallway but again will have the same issue for the discharge pipe getting to a drain.
From the hall way it would need to travel under the cellar and then up again to the outside drain...
Will provide pics in the next post...
 
Picture of cellar

20180308_221806.jpg
 
I’d say it’s not suitable as you could potentially be dealing with boiling or close to boiling water and that pump just pumps out when you turn it on. Specialist pumps can be purchased to detect when water is running through it and will pump discharge water to a drain
 
I have been looking into purchasing an unvented hot water cylinder system for when we have our loft conversion (we will have a 3rd bathroom), which is starting next week.

Due to storage constraints for the location of the cylinder, the plumbers that have viewed the property have advised either to put the cylinder (250l-300l) in the eves of the loft (which would cause a lot of disruption to the rest of the house) or in the cellar (far less disruption).

While I have been looking online at various cylinders, I have come across some forums stating that Horizontal cylinder are not as good as vertical and should be avoided unless no other choice.
One thing I could not find in addition was the exact reasons for this?
We do have a choice of having a vertical option but it would mean having two 150l cylinders side by side, which is not ideal due to the costs and setup.

We are deciding to stick with out combi boiler (33kw) and have it modified so it runs as a heat only boiler - apparently we need to have one tap that is used regularly for this setup to work (something to do with the diverter valve working properly?).

The plumber we are thinking of going with has advised we would still need to run a 22ml pipe from the cellar to the new third bathroom, where as others have said they can feed of existing heating pipes from the first floor.

Any one have any experience of setting up an horizontal unvented cylinder, especially in the cellar?
The head height we have is 1.5m and width 2m

Thank you


If I remember correctly, the reason why horizontal aren’t as good as vertical is the coil location in the cylinder. I’ve fitted several too and I had to fit a bronze pump to destratify the water, the pump mixed the water throughout the cylinder as without it, maybe a third of the cylinder didn’t heat. AND this was the manufacturers recommendations... I was quite pee’d off that I had to purchase a bronze pump.

Another important thing you should consider, is the load across the truss if it’s to be housed in the eaves, with the weight of the cylinder and another potential 250-300 kg of water, I’d seek the advice of a building engineer.

My two pennath
 
Not a big fan of the horizontal cylinders. Needs to be oversized as you don't get as much hot water as you should.
 
Don't want to "tell me granny how to suck eggs" but have the plumbers that have had a look at the job checked your incoming mains water pressure and flow rate?? You said you have a 25mm MDPE main so should be ok.
 
Don't want to "tell me granny how to suck eggs" but have the plumbers that have had a look at the job checked your incoming mains water pressure and flow rate?? You said you have a 25mm MDPE main so should be ok.

Our water pressure is 3bar and flow rate 20-22 litres per minute but that is via a water softener as well and tested from our ground floor bathroom rather than kitchen tap (as we have a quooker tap with a flow rate restrictor).
 
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Could another option be if we do fine a way of discharging the cylinders in the cellar or get a suitable sump pump, running two smaller cylinders together?

Also what brands are the best?
Obviously looking at megaflow (pretty expensive)
Joule
Telford and Gledhill

Any suggestions based on performance, warranty/parts and service?
 
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