Removing Primatic Cylinder & Installing an Indirect

[Brizy3001]

Hi All,
I'm new to this forum but would welcome some sound advise if possible.
My system is an old 1 pipe gravity fed hot water primatic cylinder with a pumped heating system.

I'm looking to update it to a c-plan system, with control of a two way valve to block the gravity flow through the hot water side; when temperature of the water is at a preset level.

Answers to a couple of questions would be helpful.

1. I'm a little unclear regarding indirect cylinders etc & think i require an expansion tank in the loft to accommodate this setup. Is this correct? or do i go for a fully sealed system?

NB: a fully pumped y-plan would possibly be better, but just awkward to impliment the way the pipe runs are etc & with piping within the concrete floors & walls.

2. Which side of the gravity feed should the valve be on?

3. Are there any other possibilities with this setup?

Many thanks
Brian

 

[Blackcatgas]

Hi All,
I'm new to this forum but would welcome some sound advise if possible.
My system is an old 1 pipe gravity fed hot water primatic cylinder with a pumped heating system.

I'm looking to update it to a c-plan system, with control of a two way valve to block the gravity flow through the hot water side; when temperature of the water is at a preset level.

Answers to a couple of questions would be helpful.

1. I'm a little unclear regarding indirect cylinders etc & think i require an expansion tank in the loft to accommodate this setup. Is this correct? or do i go for a fully sealed system?

NB: a fully pumped y-plan would possibly be better, but just awkward to impliment the way the pipe runs are etc & with piping within the concrete floors & walls.

2. Which side of the gravity feed should the valve be on?

3. Are there any other possibilities with this setup?

Many thanks
Brian

IMOP your wasting your time, you cant polish sh7t,....... but if you must.


1. yes you will need a seperate exp tank and then a new water tank while your at it, alot of older boilers require a prv type piece of equipment supplied by the manufacturer to run fully pressurised. Also your one pipe system with pipes under concrete will probably not take the extra pressure.

2. Id have it on the return personaly, as long as its after the feed and expansion connections from the new exp tank.

3. Hmmmmm, rip it out!, but if its still working Id just leave it.

 

[tamz]

You don't need to change the primatic cylinder to an indirect when changing the stsyem to a C plan but if you do you will need an F&E tank and a couple of pipes run from the cylinder to the F&E.

If your system is old enough to be a one pipe and the hot water is gravity fed you will 99% sure not be able to use your existing boiler on a sealed system. Even if it could be used, you would need to change the system to a Y or S plan. Gravity systems are not designed to be sealed.

Do a bit more research on (honeywell) C plans to find the answers to the last 2 questions.

 

[justlead1]

Hi. What fuel does the boiler burn?

 

[Brizy3001]

Thanks for advice.
System is a Gas fired Baxi Back Boiler