Home Servicing of Unvented Hot Water Systems
Unvented Hot Water systems give you it all. All the Hot Water you need as fast as you need it. They operate at Mains pressure so you get your hot water as fast as you get your cold.
Checking the relief valve on a FlowMaster Cylinder

Because it's pre-heated & stored, (unlike a Combi-boiler) there's lots of it readily available & modern cylinders are so well insulated that you loose next to no heat from them.

Your annual service will:

1. Make sure all of your safety valves are operating correctly. A tundish is provided as an additional safety measure should the relief pipe work become blocked. Water must run to drain without backing up to the tundish for the full test period.

Pressure checking on a Flow Master Cylinder

2. It will make sure that all the components fitted are as the manufacturer intended, check that the installation was installed as per building regulations & that it has not been modified out with the manufacturers guidelines.

Manufactures include MegaFlo & FlowMaster

 Tundish expelling relief water
 
3. Check & clean your filter. A very clogged FlowMaster filter Filter being cleaned  
 
A very clogged FlowMaster filter being removed from the system  
 
Filter ready to be re-housed
The safety valves will be damaged from any debris entering them so filters are important to safe operation.
These need to be checked each year. You may not notice a deterioration in performance as it will happen gradually but a blocked filter will seriously effect your flow rates & defeat the object of having an unvented cylinder.
4. Check & re-establish the air-bubble in a bubble top cylinder or pressure check the expansion vessel & correct as nessesary. (Picture top right)
 
The safety features & valves of this great system is what enables us to benefit from Hot Water at mains pressure. It does need regular maintenance to ensure optimum safety & performance.
 
5. Complete maintenance records for the system.
 
WARNING: Anyone working on Unvented Hot Water systems in the UK needs to have the current qualifications issued by BPEC. Though entirely safe when installed & serviced by competent engineers, these large vessels contain Hot Water. Mandatory safety valves are provide to make sure that whatever happens, the water cannot boil under pressurised conditions. If these valves are not functioning correctly a very dangerous & explosive set of situations can develop.
Orchard House
Donaldsons Lodge
Cornhill on Tweed
TD12 4XN
Tel: 01890 882162
Mob: 07818 067533
email: Neil Cowens here