heating control pack s type upgrade

kpbryww

Looking to upgrade with s type control pack to control hot water and rads separately and would like to know the difference between the available control packs for vented and un-vented. i understand the difference between vented and unvented system but what is the difference between the components in the control packs.

1 x 24-hour or 7-day programmer
2 x 22mm 2 port motorised valve
1 x electronic dial room thermostat
1 x 12-way wiring centre
1 x cylinder thermostat ( not included in some unvented packs)

why do some unvented packs not have a cylinder thermostat included?

kpbryww

kpbryww wrote: »

Looking to upgrade with s type control pack to control hot water and rads separately and would like to know the difference between the available control packs for vented and un-vented. i understand the difference between vented and unvented system but what is the difference between the components in the control packs.

1 x 24-hour or 7-day programmer
2 x 22mm 2 port motorised valve
1 x electronic dial room thermostat
1 x 12-way wiring centre
1 x cylinder thermostat ( not included in some unvented packs)

why do some unvented packs not have a cylinder thermostat included?

Couple of reasons:

With some boiler manufacturers the boiler comes with a diverter valve built in splitting the hot water and heating zones within the boiler.

Most thermostats for unvented cylinders are manufacture specific and come with the cylinder.

RJF

gary71 wrote: »

Couple of reasons:

With some boiler manufacturers the boiler comes with a diverter valve built in splitting the hot water and heating zones within the boiler.

Most thermostats for unvented cylinders are manufacture specific and come with the cylinder.

I think the OP was thinking more on the lines of unvented heating system than storage system. However answer still applies.

Calahonda52

May be as simple as pricing or/and its already in some single zone installs

eg in my daughters house: single zone heating system with a strap on tank stat notched into the green insulation so an upgrade pack would not need a strap on stat.
The boiler bypass valve takes up the slack

Most unvented hot water systems have a metal cover over the insulation so the strap on wont work, it need a probe type to go into the tank beyond the insulation and for safety reasons normally have two stats

kpbryww

Thank you all for your replies.

I think what I have is similar to your daughters house. Copper cylinder with green insulation. (Picture attached) Don't see any thermostat strapped to the tank and there is no room thermostat so i assume the boiler thermostat is the only control.

Its an old system in place when i bought the house and it has worked fine just now I am looking at upgrade options before I call in the plumber I like to have some understanding of the options available.

Is the copper cylinder safe in sealed system without 2nd cylinder stat?
Is it safe to use copper cylinder in sealed(pressurised) system.
I assume the system in place is sealed to provide mains pressure hot water.??(cottage single storey)
I think I need at minimum to have stat installed on cylinder and room stat.
Should I upgrade the cylinder to stainless steel to supply mains pressure hot water? Or is copper cylinder okay?

Calahonda52 wrote: »

May be as simple as pricing or/and its already in some single zone installs

eg in my daughters house: single zone heating system with a strap on tank stat notched into the green insulation so an upgrade pack would not need a strap on stat.
The boiler bypass valve takes up the slack

Most unvented systems have a metal cover over the insulation so the strap on wont work, it need a probe type to go into the tank beyond the insulation and for safety reasons normally have two stats

K.Flyer

Try not to mix up the terms "Un-Vented Cylinder" with "Sealed Heating System"

Read Gary's post above re: Un-Vented Cylinder Stat. Most un-vented cylinders come with their own stat and zone valve, so there is no point buying a pack with those items included.

O.P. your picture appears to show a typical Vented Cylinder on a Sealed Heating System.
You would be buying a standard 3 zone pack for this set up.

RJF

kpbryww wrote: »

Thank you all for your replies.

I think what I have is similar to your daughters house. Copper cylinder with green insulation. (Picture attached) Don't see any thermostat strapped to the tank and there is no room thermostat so i assume the boiler thermostat is the only control.

Its an old system in place when i bought the house and it has worked fine just now I am looking at upgrade options before I call in the plumber I like to have some understanding of the options available.

Is the copper cylinder safe in sealed system without 2nd cylinder stat?
Is it safe to use copper cylinder in sealed(pressurised) system.
I assume the system in place is sealed to provide mains pressure hot water.??(cottage single storey)
I think I need at minimum to have stat installed on cylinder and room stat.
Should I upgrade the cylinder to stainless steel to supply mains pressure hot water? Or is copper cylinder okay?

Yes, the cylinder is safe but inefficient. It is not a 2nd stat, there is no stat on cylinder. There is stat on boiler to regulate flow of hot water through cylinder. (coil, i.e. heat exchanger)
Yes, it is safe to use in a sealed system.
No, it does not provide mains pressure hot water. It is not an unvented cylinder. The heating system is unvented, the hot water storage is not (i.e. it has a vent to large tank). The pressure in the hot taps is dependent on the height of your storage (large) tank.
A cylinder stat, room stat and zone control will make your system more efficient.
Copper cylinder is ok if you are happy with current pressure of hot water at taps. Should check for leak though, from the look of the brown stain.