C plan to S plan fully pumped

[bhm1712]

anyone? sorry if im boring and going over stuff.

I dont want to go down the route of bodging a second pump into the HW circuit. I just want to go fully pumped safely and as simple as i can

 

[yodaveg]

would that be allowed then? fitting the MV in the returns on an S plan?

wouldnt the water be pumped into the F&E tank at a fair rate if the valves were fitted either way (in the flow or return) ? surely it would, and thats the point isnt it?

If i kept both sets of pipes, it wouldnt be compliant as far as im told..modern boilers dont come with twin tappings so if it failed i would be back to square one with altering pipework.

Ive fitted M valves to the returns when you can't get to some of the pipework (tiled, real wood floors). Basically when it looks like your job.

If the M valves failed and they were on the flow they would hold the water back from the tank. so little pumping over would occur.

I didn't think you were changing the boiler so having two sets of pipes would surelly not matter.

I still think pressurising the system would be your best option.

 

[bhm1712]

What i mean though in terms of pumping over if the valves are in the flow, is that if the system is as it should be, the vent should be before the valve, so if the valves failed it would pump over into the tank to prevent over pressure and pipe burst/boiler explosion.

will the first few rads get warm with the valve in the return when the HW is on? or will it be ok? i am assuming so, because at the moment my HW valve is in the return and the cylinder doesnt heat up with just the CH on.

No your right, im not planning to swap the boiler, but i dont want to spend money on modding the current setup, only to have to spend more again if the boiler failed and i had to have a new one. I want to set it up so that if the boiler does ever fail then i only have to buy a new boiler, and have minor alterations to pipework.

 

[yodaveg]

Possible pipework

 

[yodaveg]

Possible pipework, further explanation to follow:

Pipework

• yodaveg
• 5 Dec 2011
• 1

 

[bhm1712]

i can see where your coming from. Looking forward to explanation!

 

[yodaveg]

1. pressure gauge
2. expanssion vessel
3. pressure relief pipe
4. temporary filling loop
5. auto air vent

This way you could get rid of the small F and E tank in the loft. Also the vent pipe could be cut down and have an auto air vent fitted. The cold feed could be turned into cold mains and used to fill the system via a filling loop.

 

[bhm1712]

im liking it! thats just cleared things up in my mind. Im a controls engineer not a plumber/pipe fitter so i can 'get me head round electrics and controls' no problem, but pipework....it takes me a little longer!

 

[yodaveg]

No worries mr!

Most modern boilers detect how much pressure they have in them, this is one of the reasons they are more efficient as water heats up better under pressure. Your boiler doesnt have this so we could run the system with very little pressure so not to put strain on old pipework. If you imagine your system as an empty bottle, all we are going to do is fill it and put the lid on. We are not going to put extra pressure on top.

The pressure relief valve must be terminated in a safe place ideally outside about 4inch off the floor and aimed back to the wall a touch, you can even get a gaurd to protect kids and loonies who want to put their face near it.

Filling the system maybe fun, as you would need to see the gauge, vent the rads and man the filling loop all at the same time.

 

[bhm1712]

the bathroom is above the boiler in the garage, and so getting a proper permanent cold mains feed down into the garage wouldnt be a massive task to be honest so that might be the best solution to begin with.

 

[yodaveg]

http://www.screwfix.com/p/expansion-vessel-control-kit/92562

http://www.screwfix.com/p/expansion-vessel-mounting-bracket/86194

http://www.screwfix.com/p/expansion-vessel-12ltr/46517

Just to give a rough idea of what it all looks like and some costings.

 

[yodaveg]

the bathroom is above the boiler in the garage, and so getting a proper permanent cold mains feed down into the garage wouldnt be a massive task to be honest so that might be the best solution to begin with.

Sounds good just lagg it really well, garages get v cold. Do it in plastic for extra protection.

 

[bhm1712]

thankfully, my house is mid terrace with a built in garage, so the garage site between my living room and next doors living room so its almost as warm as the main house inside! i have lagged everything else in the garage and airing cupboard anyway for savings and protection. the boiler pipe lagging needs attention as you can see in the pic

 

[bhm1712]

in terms of system pressure what would be ok for my glow worm space saver?? i have calculated roughly that currently there is about 6psi of head so thats 0.4 bar. I have been told (rightly or wrongly??) that anything less than 0.5 bar cold in a sealed system wont work.Is that right?

Plus, will my boiler be ok with a sealed system? the manual i have doesnt mention anything about suitability as its 23 years old and i assume it wasnt the normal for sealed system back then. i dont want to convert only to find i blow something up

 

[45yearsagasman]

If it doesn't have overheat protection and the manufacturers do not mention sealed systems then it is not permitted for that boiler.