System Boilers
System heat-only boilers
A system boiler, just like an open-vent boiler, works excatly as a conventional boiler above, however the need for a feed and expansion tank is removed, and we commonly use the term "sealed system" .There is a pressure gauge on the boiler, and a method of letting water into the system normally via a filling tap. Some system boilers also have the pump built in, so there are less components elsewhere on the system.
System boiler with pressure gauge |
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Generally speaking, a "sealed system" tends to suffer from airlocks a lot less (whereby awkward pipe runs cause air to stop the water flowing to certain radiators), and also radiators tend to warm up quicker. Once again, because there is no tank in the loft, one can install a system boiler at the highest point of the house
Coupled with a high recovery cylinder (a cylinder with a very fast warm up time), or an unvented cylinder (mains pressure water storage), it is the ideal choice for the family home which needs every inch of space for storage and has a high demand for hot water.