non existant pressure!!!

[Bigron]

Hi All.
I've been watching the forum for some time now and have gained many useful tips without the need to post, until now.
We recently moved into a 4 bed house and have had the monster of all gas bills over winter. I knew the existing CH system was old and inefficient but my hand is forced into changing it much sooner after £230 on 1 months gas!
With 2 kids I want an unvented system as i think stored heat will be more economical for us.

There in lies the problem, had a guy round today to do a pressure test. He says we getting 5 bar static but just 1/2 bar flow. meaning we cant go for an unvented system. I dont want to get a new supply into the house as it would mean a water meter as I understand it and I've been down that road before and unless your a camel they're expensive to say the least!

After a bit of thinking I came up with the idea of a large header tank with a pump on it eg. 210L cylinder (megaflow) 250L header tank with pump. As we only have one bathroom the extra 40L would act as a buffer while the tank tops up.

What I need to know before I go getting quotes is the general idea of viability, can it be done? or am I wasting mine and others time.

Any ideas would be greatly appreciated.

 

[Puddle]

Nothing wrong with fitting tank and pumping through water supply but seems alot of fuss to provent a water meter being fitted
we are all going to have them sooner or later
What happens when you go to all the expence of fitting tank and pump,leaving your mains small size,get all sorted and then a letter comes through the door saying,we are renewing mains supply in your area or your area is being updated and a water meter is being fitted to your supply,you have just wasted a lot of time and money

 

[WHPES]

Any inefficiencies are more likely to be down to system design. A well designed vented system can be very efficient if done properly.

Is your boiler old? Modern boilers are high efficiency condensing boilers. What about insulation - have you got plenty of loft insulation, cavity wall insulation, double glazing etc? Do your doors and windows seal properly when closed? Is your radiator system properly balanced? Is it full of sludge? Are exposed pipe runs insulated?

 

[Cds]

5bar static but only 0.5bar dynamic would seem low, what flow rate was the dynamic taken at?

Range does a vented arrangement (Kernel Unit) with pumps after the tank/cylinder to give you 3bar on both cold and hot water. Have a look at even if only to get some ideas: http://www.range-cylinders.co.uk/product-kernel-plumbing-units.html

I used one at my last house; the only problem as with all pumped system is these can be a bit noisy.

 

[Bigron]

Hi guys,
Whpes yes the insulation, double glazing and doors are all well up to scratch. The problem is the boiler. It's 25yr old and according to EST it's X rated and was 62% efficient when installed it's a Baxi Boston 70 H! And the rads are the same age and woefully inefficient (they get really hot but take forever to warm a room so prob undersized too). Im planning to renew the whole installation but might not be in one go. Thought I'd get the boiler done first to get the scrappage discount.

Puddle, as for the water meter, we tried it when we were m
renovating our last house and stayed in the one I rent out. What normally costs £300 a year cost £600 for 6 months (we got a 1 year old the washer is never off!). So the longer I'm off a meter the more I save towards the new system. Although I know I'll have to have one eventually.

Cds I'll check the link out tonight.

Thanks

Hi guys here's what i've come up with so far to defeat my lack of pressure.

either somwthing like this:
Altecnic Ultra Pro Expansion Vessel with interchangeable membrane for Potable Water Vertical 200ltr

or a standard header tank with pump on it.

Would this then allow me to use a unvented cylinder. The only problem i can see is wether or not I would need some sort of protection to prevent the cylinder from drawing in air if someone leaves a tap running?

The next snag I've hit is height. In order to get the cylinder out of the bathroom (the minister of war wants the extra room) im restricted to the height of the eaves in the ground floor loft 1Mtr.
Can I use a horizontal cylinder or am i better off getting 2 smaller cylinders to run in parallel?

As im sure you lads can tell I like a challenge. LOL
P.S I'm an electrician who works on control systems

 

[Bigron]

Any one have any reasons why i cant run 2 cylinders in parallel fed by an oversized header tank with in line pump?

It looks like the best way to accomadate what i want into the space I have is 2 cylinders or a single horizontal one.

 

[WHPES]

You can run 2 cylinders in parallell but working out the controls is going to be a headache for your electrician! Effectively you will need to split your heating circuit into 3 zones, each independently controlled by its own zone valve. Depending on how it is at the moment, it may require extensive modification of the pipework.

You can't lay a cylinder horizontally as it just won't work. You would have to use a calorifier instead (expensive).

Also, it's going to be very expensive so why not look at that new supply pipe again and an unvented system or combi boiler?

 

[Bigron]

hi Whpes,
I am going to look at a new incoming supply but am unwilling to have a meter for as long as I can get away with it.
The reason I want to use 2 cylinders is I'm restricted with the height where I want to locate them. That's why I looked at horizontal cylinders which like u say are about 1/3 more expensive.
It's also going to be a completely new install as this is where I plan on staying (done 3 houses up now and am fed up now).
As for the wiring, I'm an electrician dealing with industrial machine controls and automation so just a different challenge really. Lol

got BG and N Power coming next week so that should be fun.

 

[Bigron]

Re: non existant pressure!!! update

Update!
BG round today. Very nice man and knowledgeable to boot.
However the list of things they WONT do is extensive!
They wont pump from a header tank to create an unvented system.
They wont mount a cylinder in the loft space above the kitchen (extension) despite an structural survey saying its suitable to be used as a floor if built on.
They wont provide cylinders in parallel.
They wont provide horizontal cylinders.
And will only supply certain boilers to be used in a loft space.

So I asked why.
The answer: BG health and safety policy.
So I ask is it unsafe,
The answer: not from a plumbing point of view and many installers will do it for you but BG wont.
He was well on top of what i wanted and even suggested better ways of doing it but just that BG wont.

He's going to quote for a vented system with a small cylinder and closed heating system, but cant on site cos BG servers down.

All in all an interesting visit then.lol

Im looking for recomendations in terms of reliable installers in the North Manchester area.
Im not fixed to what I want and am more than willing to accept advice, just would like it to come from someone who sounds like they know what there doing as opposed to selling me the easiest system to install.

Regards

Ian

 

[oldplumber]

Why have you no pressure on your cw main, is it poor throughout the area or is your incoming main old and blocked. If it is the 2nd, run a new 25mm mdpe pipe yourself from the water company stopcock. All you need is a shovel and min of 750mm trench to lay a new pipe upto your incoming stopcock in your house. If you use an approved plumber you dont need the water company approving the new water main etc etc. Then you can run an unvented cyl as you wish. Dont forget the supply from the street to your house is your responsibility anyway so diy.
If the low water pressure is the problem of the water company, get them out to do a pressure check and confirm why its so low. I had a case at christmas where a large plumbing co had connected up a combi 2 years back and it took the tenant 2 hours to run his bath!!!! Turns out the water co had renewed all the supplies onto a new main in the road, but reconnected him up to the old supply again. Only their visit to check the pressure resulted him being reconnected and able to run a bath in 10 minutes, pity his original plumber hadnt investigated further and not gone ahead and installed a combi in the first place.

 

[Bigron]

Thanks Oldplumber,
At present were on a common main, would like a new supply but that would come from the front of the property where at present we are fed from the rear. not a problem to really to run a new bit of pipe ( wooden floors 100yr old property)
Also as far as im aware a new supply would mean a meter on it would it not?

Do you think replacing the service pipe from the existing supply would make a difference?
Not sure where the existing supply runs, there is a chance it could be under the out house!