Combination Copper Hot Water Cylinders

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Combination Copper Hot Water Cylinders by Gledhill

FORTIC TANK - Hot water cylinders with built in header tank

Index Page > Hot Water Cylinders > Combination Hot water Cylinders

What is a Combination hot water cylinder?

A combination cylinder (also known as a Fortic Tank) is one that incorporates a cold water header compartment instead of a separate header tank. The convenience of a simple one-piece installation is clear and the design lends itself to properties like flats or apartments where a lack of loft space makes it difficult or impossible to site a header tank.

Drawbacks of combination type hot water cylinders

Combination cylinders are not the best solution to all installations. Resulting hot water pressure from a combination cylinder can be poor if the header section (the bit that creates gravity pressure on the cylinder) is at a low height above hot water outlets in the property. (note: the higher the header from the outlet point, the higher the pressure due to gravity)

For this reason, combination cylinders are only used when necessary, not as a first choice.

Low pressure from a combination cylinder can be frustrating. Mixer showers tend to suffer noticeably. The temptation exists to install a booster pump to improve performance, but consider carefully before you do so. The volume of cold water contained within the header can often prove inadequate to keep up with the extreme demands of a booster pump so you risk running your system dry fairly quickly. This is not good for the booster pump and can cause damage.

All cylinders are fully insulated with a thermally advanced and environmentally friendly jacket, offering continued high performance throughout the life of the cylinder. At the end of it's life the insulation decomposes so it's also environmentally friend too.

Speed, Superior Quality and check out these discounted prices...

Indirect combination hot water cylinder showing boiler coil, optional immersion heater and cold water header compartment with float valve

Above: A schematic showing how combination cylinders work.

Combination hot water cylinders can be either Direct (heated by an immersion heater only), Economy 7 (fitted with two immersion heaters and extra thick insulation) or Indirect (fitted with a boiler coil and immersion heater/s). Indirect cylinders can be made to an Economy 7 pattern.


Direct and Indirect combination hot water cylinders explained

A combination hot water cylinder incorporates a built-in cold water header compartment.

Can be heated exclusively by an immersion heater (Direct model), or can incorporate a boiler coil and electric immersion heater (Indirect model).

COMBI Cylinders were historically known as 'Fortic Tanks'

Direct Combination Copper Water Cylinder



Copper DIRECT Combination hot water cylinder (Fortic Tank, Immersion tank)

Copper DIRECT Combination

water cylinders

ex VAT inc VAT  
900 X 400 Direct Combi Tank          282.17 338.60  
1050 X 400 Direct Combi Tank         297.15 356.59  
900 X 450 Direct Combi Tank          297.70 357.24  
1050 X 450 Direct Combi Tank         310.41 372.50  
1200 X 450 Direct Combi Tank         329.41 395.30  
1400 X 450 Direct Combi Tank         393.76 472.51  
1500 X 450 Direct Combi Tank         417.52 501.02  
1800 X 450 Direct Combi Tank         454.59 545.51  



For Economy 7 model please click here







Copper INDIRECT Combination hot water cylinder (Immersion tank/Fortic Tank)

Copper INDIRECT Combination

water cylinders

ex VAT inc VAT  
900 X 400 Indirect Combi Tank        324.42 389.30  
1050 X 400 Indirect Combi Tank       335.74 402.89  
900 X 450 Indirect Combi Tank        335.74 402.89  
1050 X 450 Indirect Combi Tank       343.66 412.40  
1200 X 450 Indirect Combi Tank       364.27 437.12  
1400 X 450 Indirect Combi Tank       434.95 521.95  
1500 X 450 Indirect Combi Tank       452.38 542.85  
1800 X 450 Indirect Combi Tank       491.70 590.04  



For Economy 7 model please click here




Additions and optional extras

Options available at additional cost include:


Compression fittings (instead of threaded bosses)



Shower take-off



Additional Tappings (pairs)



Secondary return



Immersion Heater (Incalloy) 3kW alloy coated (corrosion resistant)



Drain valve (drain cock) [threaded boss included on cylinder]



Hi recovery boiler coil (pumped)



Super Recovery coil (Pumped)



Ball valve and overflow (supplied loose - not installed)



Additional immersion boss (already supplied with one)



Gravity boiler coil with 28mm connections

(Large bore for AGA, wood burner, unpumped heat source etc)


(please add to stated price)

Positioning tappings to your specification does not normally attract a supplementary charge


When sizing a cylinder remember the stated dimensions do not include the thickness of insulation. You must add the thickness of insulation to the cylinder dimension to obtain the finished size. This is most important if the cylinder needs to pass through a doorway or access hatch. Make sure you have enough room to make connections and service immersion heaters.

Illustrations are for guidance only and should not be interpreted as an exact representation.


Note: Cylinder illustrations are for guidance only. The relative location of the hot water outlet to the immersion heater may be positioned to customer requirements thereby enabling easy fitting/retrofit. Please refer to Designing a Cylinder section.

In the cylinder industry nothing should be assumed or regarded as 'standard'. Features such and as the position of connections, a shower take off, drain, boiler control stat/sensor pocket or any other item should be stated as a requirement, not assumed.



For ECONOMY 7 Combination Cylinders please click here

January 2022

Combination Copper Hot Water Cylinders



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