Mains pressure hot water

[Butty21]

I’m looking at replacing my cylinder as I damaged it while replacing an immersion heater element. What I’m looking for is a system that will give me good pressure and reduce the temperature of the hot water as sometimes its to hot.

Current setup 3 bedroom house with single bathroom
1. Solid multifuel stove with back boiler 4 ports two 28mm gravity feed / return to cylinder and two 22m feed/ return for central heating .
2. Central heating pump is located next to boiler downstairs
3. Cylinder is indirect vented.

I would like something like a DPS heatbank Pandora but cheaper and only does the hot water as the central heating works great.

Any recommendations !!

 

[Agile]

You have to get a special cylinder if you want to use a gravity hot water heating.

The obvious solution is to convert your old system then you can use unvented cylinderds etc.

An unvented has to be installed by a competent installer with the right certificate.

Tony

 

[tamz]

You could use a vented thermal store which works like a back to front cylinder whereby the boiler directly heats the full contents of the cylinder. Mains water is run through the coil and out through a blending valve to control the temperature. This will give you mains pressure to your hot water. Presumably your cold is fed from the storage tank. This can be done away with so the full house is off mains pressure.
Btw it sounds like you need a pipe stat on the HW circuit or if you have one already it needs adjusting.

 

[Agile]

On a gravity system the temperature of the hot water is controlled by the boiler stat.

He obviously has that too high.

But he probably needs it high to get enough heat during the heating season.

Yet another reason NOT to have a gravity hot water system!

Tony

 

[tamz]

The OP says he has a

Solid multifuel stove

which i take to be solid fuel.

 

[Butty21]

Thanks for the response

The system is solid fuel (coal) so if the fire has been lit most of the day the water in the cylinder is very hot.

I have looked at the DPS xcel and the basic unit is about £2000 which is a cylinder with a plate heat exchanger.

I have also looked at a whole house pump, but have been put of by the reports that they are noisy.

I think I have added a diagram of the current system

Untitled

• Butty21
• 2 Sep 2009
• 1

 

[Goldspoon]

Replace your cylinder with the same but new.

Add a Salamander (or similar) pump to the hot water 22mm as the first item after the cylinder.

You might have to increase your loft cistern size.

 

[tamz]

The Dps xcel is a good unit but maybe a bit overspec for what you need unless you are planning on adding various other heat sources. Also if you have a power cut (assuming you are in a quite rural location) you will have no hot water even if the heat bank is full as it depends on the pump to circulate through the plate heat exchanger.

Possibly a better option would be a direct cylinder version of this
http://www.mcdonald-engineers.com/images/literature/Therm Flow Lft.pdf

All the other cylinder manufacturers do similar versions (eg Albion mainsflow, Range flowmax)
They are also available with extra tappings for additional heat sources.

A cylinder version would allow you to keep your exiting F&E tank and cylinder position without too much alteration to pipework.
You wouldn't necessarily have to use the heating tappings on this cylinder but it would be preferable if you did as your heating would work much more efficiently.
Also go for the biggest unit you can fit in to store all that uncontrolled energy.

Speak to the cylinder manufacturers, they are mostly very helpful.