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HIGHER PRESSURES AND
FLOW RATES UNVENTED: limited in the pressure they can supply to taps by a pressure reducing valve, typically in the region of 3 bar. Heat Bank Thermal Store: pressures up to 9 bar to hot taps, mains providing. Especially useful when using pump sets that can provide 6 bar pressure - some installations require it. |
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NO DISCHARGE PIPES UNVENTED: require a discharge pipe and tundish to protect against over-pressurisation of the store. Common for discharge to spill over tundish onto floor. Heat Bank Thermal Store: requires none on Pandora models. |
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NO SPECIAL TRAINING NO NEED TO NOTIFY BUILDING INSPECTOR UNVENTED: Must posses an industry recognised certification to install or service as per building regulations: It is a legal requirement that the local authority Building Control Officer be notified of any proposed installation of unvented storage water heating systems over 15 litres. This notice should include:- (a) Name, make, model and type of hot water storage system to be installed. (b) Name of the body which has approved or certified the system. (c) Details of the ‘competent installer’ intending to carry out the work, including details of any current Registered Operative Identity Card held, and the issuing body. Heat Bank Thermal Store: requires none (Electrical regulations apply). |
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NO ANNUAL MAINTENANCE UNVENTED: should be regularly serviced to check operation of safety controls. Cylinders using an internal bubble for expansion may also need this re-charged to prevent dripping discharge pipe. Heat Bank Thermal Store: requires no regular maintenance, other than addition of fresh corrosion inhibitor (£10 from a any plumbers merchant) every 3-5 years. |
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NO LIME-SCALE BUILD UP IN STORE UNVENTED: as water is heated, limescale is deposited onto the inside walls of the cylinder, and on heating surfaces. Fresh limescale is introduced with each draw-off, and this cannot be flushed out. Heat Bank Thermal Store: it is the same water in the store in 10 years as the day it was installed, so no limescale build-up. Plate heat exchanger is relatively immune, but can be easily flushed if needed. |
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BALANCED HOT AND COLD
PRESSURES UNVENTED: The cold water supplies if fed directly from the mains, may be at higher pressures than the hot. To overcome this, and to prevent possibility of higher cold pressures back-feeding into the unvented store, the cold supplies should be taken via the pressure reducing valve supplied with the unvented store. This requires extra pipework, and reduces cold pressures. Heat Bank Thermal Store: No need for any pressure reduction (unless over 6 bar!) so hot and cold are all at same pressures, and cold pipes can be branched off mains prior to reaching cylinder. |
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CHEAPER OVERALL UNVENTED: Unvented stores cost approximately £150 less than the Heat Bank Thermal Stores of same capacity, but they come in kit form, and all but one of the above cost money. Heat Bank Thermal Store: A fully assembled and wired. Simple to install and cheap to maintain, shown over many years to be reliable. |
| All the advantages, None of the disadvantages. | |
