Attended this job in Fremantle with the client complaining of fluctuating hot water and slow temperature creep from all fixtures. After first checking the water pressure to the villa, then the flow rate I noticed that the electrician who installed the hot water unit failed to commission it correctly. It might not be obvious from the photo however the incorrect isolation valve has been used on this unit and the electrician under his restricted plumbing license in unable to replace it for a correct valve (Full flow ball valve)
Often the repose I hear is “Why do I need to change it? It’s the original valve? It worked before!” Firstly, aging valves of this design significantly reduce flow into the unit. As the Wilson is a mains pressure hot water system that relies on flow to activate the heating system, having a reduced flow straight away effects the operation of the unit. It also voids the warranty for this type of hot water system, as a stop cock doesn’t allow reverse flow back into the cold water system – Any full flow instantaneous hot water unit requires full flow ball valves as per manufactures installation instructions and the AS3500.
I fixed the issues at this properly by installing a better flowing shower head, replacing the valves to the correct type, commissioning the hot water unit correctly and cleaning the strainer which the electrician failed to do. This job should of been carried out by a licensed Plumber, who would of ensured the unit was commissioned correctly and installed to Australian Standards 3500 / Manufactures installation requirements. Forchanely I was able to complete the repairs quickly with stock that I carry on board, minimizing the cost to the client – However, it would of been cheaper for the client to engage a Plumber to install the unit rather than an electrician.