07/04/2024
Most houses in the estate I reside have an indirect mains-fed cylinder providing the hot water, similar to the attached photos, with heat provided by a gas boiler.
Often hidden away in the cupboard these units are neglected until something fails with some I've attended burst due to lack of maintenance.
The manufacturers recommend an annual service on these with most tanks themselves having a 'lifetime' warranty if serviced annually, which is very seldom done with the emphasis always on the gas boiler.
These unvented cylinders are just as dangerous and can be more so than a gas appliance if tampered with or not maintained properly.
I carry out gas boiler services in the estate for £50 and have recently completed additional training and become accredited through NICEIC to carry out the annual service and installations of unvented water hot systems.
As an introductory offer, I will be carrying out services of these units for £95 and if carried out in conjunction with your boiler service £85 - both for £135
Drop me a message if you need to discuss this or any other heating, plumbing or gas issues.
WHAT’S DONE ON AN UNVENTED HOT WATER CYLINDER ANNUAL SERVICE?
You’ll find the exact requirements for the service in your cylinder’s maintenance manual, which the heating engineer will sign on completion of service if available.
I can supply my own company checklist on completion of the annual service if required if the manual is lost.
Here’s an example of what checks we would carry out on an unvented hot water cylinder.
Heating
• Check the pressure on the heating system expansion vessel (1-1.5 Bar)
• Test the operation of the pressure relief valve
• Top up the system if required and check the operation of the filling loop
• Check the filling loop for leaks and rectify where required
• Test the operation of the central heating flow two-port valve (Zone 1) manual �and automatic fires on demand
• Test the operation of the central heating flow two-port valve (Zone 2) if �applicable
• Check the electrics at the wiring centre
• Check the manual bottle air eliminator and vent any excess air in the system
• Check the operation of the controller to ensure manual and automatic operation
• Check the operation of the circulating pump and test the load
• Check the operation of the secondary return pump (where applicable)
•
Hot Water
• Check the pressure in the expansion vessel (3 Bar)
• Test the expansion relief valve on the inlet control set for correct operation
• Test the temperature relief valve for correct operation
• Clean the mesh filter on the mains inlet set
• Test the operation of the immersion heater and check the load
• Check the immersion heater thermostat and water temperature
• Test the operation of the dual thermostat for correct operation
• Test the DWH 2 port valve for automatic and manual operation
• Check the operation of the controller to ensure manual and automatic operation
Note: additional parts and labour will be charged extra if a return visit is required to rectify any faults, this will be quoted for.
Before any annual service on gas appliances or unvented cylinders are carried out we recommend you ask the engineer for proof of accreditation before proceeding.
I've attended homes recently where gas work has been carried out incorrectly and left dangerous by unqualified engineers, often friends or family.
Please don't take the risk.
I won't share the links but a quick search of 'unvented cylinder explosion' on YouTube will show you the damage that can be done by a faulty unit.
