DIY Heat Bank Part Deux

[Agile]

I have this thought in my mind that my Father took me to a foundry in East Anglia however all the web history shows it as being in Wolverhampton.

It was very successful until after the second world war when it went through many financial disasters and went into liquidation many times. It still apparently survives as Crane Cast following the last liquidation about 2001.

When I visited it was mostly making large brass water valves although it has made almost everything that can be cast in steel and brass at various times in its history.

I dont think you will find any significant technical support from anyone but its such a simple boiler it does not need any.

Tony

Tony

 

[htgeng]

He doesn't need the controller - he could do with the rest.
.

I'll stick it on an ebay 'buy it now' for the external pump, exchanger and sensors.

 

[Agile]

What is your ebay name?

Do you go to Morris Miller's IPHE Cambridge branch meetings?

Is he really as good looking as he makes out?
Did he get any fan mail after his appearance on Test the Nation ?

Tony

 

[htgeng]

What is your ebay name?

Do you go to Morris Miller's IPHE Cambridge branch meetings?

Tony

Am a little coy at giving that out on a public forum, but I will email it to you. I've never been to the Cambridge meeting. I forget when they are scheduled and well I guess I've always got something else on my plate - either work or gym.

 

[Softus]

I am removing a Pulsacoil unit from a customers house in the next couple of weeks. The landlord is mightly p****ed off that it keeps locking out causing the tenants to give him grief.

The problem is the poor pcb's (probably a bad batch), not the thermal storage.

It would be much simpler to fix the Pulsacoil rather than decommission it. And I've maintained heaps of these things without once seeing a faulty PCB.

If it keeps locking out then one of the IH thermostats is faulty, or the overheat thermostat - in the latter case just remove it and replace the IH stats with EN 60335-2-73:1996 compliant ones (which is what Gledhill have started doing).

 

[fumb]

I dont think you will find any significant technical support from anyone but its such a simple boiler it does not need any.

Sadly this is the main thing that's going to kill it off. The guy who normally did the annual Landlord cert also used to service it at the same time. However, he's now not alowed to do the service due to aspestos being present and I can't say I blame him for that

I don't mind messing with vented plumbing because if I make a fist of it the worst thing that happens is I get wet feet. I don't mind messing with mains electrics because the worst thing that happens is I switch on the lights, my hair stands on end and I hop round the room swearing a lot. I won't touch gas because the worst thing that can happen is a huge bang that I know nothing about
So no boiler servicing means, for me, the boiler has to go

On a brighter note my local plumbing shop guy reckons he can probably get hold of a suitable heat exchanger for not to much money.
I also discovered that he knows the man who gave his idea to Mr Gledhill back in the 70s. Didn't realize this sort of technology had been around that long! It gives me a little more confidence to have a go

 

[fumb]

You dont need 80 to 85 C inside a directly heated heat bank. Thats a myth.
70 C is fine especially with a good plate heat exchanger fitted and you will still acheive a higher percentage of condensing compared to an indirectly heated cylinder heated to 60 C.
What people dont understand is you cant transfer the heat quick enough when heating indirectly via a coil.
Heating directly is faster and more efficient. A good heating engineer who understands the finer points about heat transfer in water thermal systems will know this.

I have an indirect cylinder. I now know that I can convert this to direct heating with a couple of Surrey type flanges in the existing feed and takeoff points in the cylinder.
My question is this. If I go down that route do I run the risk that water being fed to the top of the cylinder from the boiler will be fed directly out of the takeoff on top of the cylinder
The issue is that currently I have about 15' of piping between boiler and cylinder. When the boiler is off the hot feed pipe is going to cool down. When the boiler restarts the cold water from the feed pipe is going to be fed into the top of the cylinder. As far as I can see if this gets "sucked" directly out of the top of the tank again there's going to be cool water coming out of the tank for a short while until that "standing" cool water has been cleared

Am I correct about this or does the Surrey type flange actually prevent this from happening

Cheers
FD

 

[Bigburn]

Fumbduck wrote

My question is this. If I go down that route do I run the risk that water being fed to the top of the cylinder from the boiler will be fed directly out of the takeoff on top of the cylinder .

You mean fed directly to the inlet side of the plate heat exchanger. Yes ,possible but only when the boiler pump and plate operate at the same times which wont be very often.

The issue is that currently I have about 15' of piping between boiler and cylinder.

28mm pipe ?. About 3 liters.

When the boiler is off the hot feed pipe is going to cool down. When the boiler restarts the cold water from the feed pipe is going to be fed into the top of the cylinder. As far as I can see if this gets "sucked" directly out of the top of the tank again there's going to be cool water coming out of the tank for a short while until that "standing" cool water has been cleared

The 3 liter glug of cooler water that was in your 15' of pipe wont be going or sucked anywhere.
What you have happening is temperature dilution occuring and the heat exchange between the two temperatures at the top of the cylinder is almost instant which will lower the temperature at the top slightly but the boiler will quickly recover this.
Should the plate heat exchanger pump be operating (ie someone turns on tap and flow switch energises plate pump) then the temperature drop to the primary side will not adversly effect the HW temperature on the secondary side .

 

[fumb]

Doh! Cheers for that Bigburn,

I can see I've been a bit of a tw@ here.

I have confused the switching of the plate exchanger pump with the switching of the boiler circuit pump. I was imagining that every time you turn on a hot tap the boiler circuit is going to fire but that's not going to be the case I can see now

 

[fumb]

Hello Gentlefolk,

An update

I started work on this yesterday and am pleased to announce that as of right now IT'S ALIVE . I'd also like to breifly swear at whoever invented galvanised imperial pipework

Many thanks to all them as contributed advice......

I've ended up with the hot cylinder still indirect gravity heated exactly as per my original drawing. I discovered that from fireup the boiler isn't man enough to provide hot water quickly. Until the water jacket is up to temp (about 2-3 minutes) it's mostly cold/lukewarm water that comes out which I figured would have caused issues if direct heating the cylinder

I'll post up some pictures tomorrow if anyone is interested. Right now I'm off for a celebration beer or 12

 

[ChrisR]

if anyone is interested.

I reckon you could sell tickets!
If it works, let's all say Well Done before the carping starts about it not looking pretty...

Is your "what I had in mind" drawing accurate now?

 

[Bigburn]

I've ended up with the hot cylinder still indirect gravity heated exactly as per my original drawing. I discovered that from fireup the boiler isn't man enough to provide hot water quickly.

I would suggest it has nothing to do with you boiler being man enough but more to do with the fact that you are relying on gravity circulation to heat the cylinder of water.

 

[fumb]

Well here goes,

Nomex suit donned. At least I know I have plenty of mains pressure hot water to put the flames out

I made one rookie error (that I know of ). The 15mm plastic is the vent to the header tank. Naturally (I can see it now ) this sucks air when the pump kicks in . I have temporarily blocked it and will replace this with a screw type vent tomorrow. In the mean time it's running with a combined feed/expansion

Ignore the **** poor wiring. I discovered at about 6pm that the roll of flex in the garage was coax and just grabbed the first wire that came to hand

Still, so far it's working great. I had a lovely hot bath tonight although due to an oversight (bath mixer cold feed plumbed directly to cold water tank, forgot that) the shower doesn't work lol

Still, I'm pretty impressed. Total expenditure sub 200 squid which seems quite reasonable to achieve mains pressure DHW and get rid of the rusty loft tanks

Burn, never even thought about that. I guess it would take a significant time for gravity to take effect. Oh well, system works just fine so I'll live with it as is

Eagerly awaiting the arrival of Jesus H. Christ
Steve

 

[Bigburn]

I can see the flow switch on one side but the outlet on the other side of the plate seems to T back into the pipe connected to the cylinder between what looks like a chrome isolating valve (or could be a non -return valve) and a galvanised pipe in the corner.
Can this be right ??.

Whats the galvanised pipes purpose in the right hand corner and what is the chrome isolating valve for or is this a non return valve ??

 

[fumb]

I can see the flow switch on one side but the outlet on the other side of the plate seems to T back into the pipe connected to the cylinder between what looks like a chrome isolating valve (or could be a non -return valve) and a galvanised pipe in the corner.
Can this be right ??.

Whats the galvanised pipes purpose in the right hand corner and what is the chrome isolating for or is this a non return valve ??

Ah, well, you see

I hedged my bets. The galv pipe is the hot water piping. Originally the cylinder was directly connected to that.
Whilst I had every faith in the system I wanted to make sure that if everything went pear shaped I could etill use the old setup
So the silver thing is indeed an isolator. If I kill the cold main into the flow switch (there's another isolator just visible below the pump) then I can open the one on top of the tank and I still have gravity fed water. At the moment I'm using the old water tanks in the loft as the F&E for the cylinder so I'd just swap back to a known working solution
It could have been simpler if I'd really believed in myself lol