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Andrew Smith
Andrew Smith, Engineer
Category: UK Plumbing
Satisfied Customers: 3632
Experience:  Domestic Gas, Commercial Gas, LPG, Unvented Hot Water, Part P Electrical, Commercial Catering
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My name is ***** *****. I have a Hercal 1050 x 450mm OD hot

Customer Question

Customer: . My name is ***** *****. I have a Hercal 1050 x 450mm OD hot water cylinder (vented system) with a Potterton PTt100 controller. The problem is it never turns off, even when the water tank is full. I guess it needs a new controller/probe. Is there an alternative, as I can't find one? Regards Neal
JA: Thanks. Can you give me any more details about your issue?
Customer: When the system is heating water, the gas boiler just keeps on running, so I have to keep turning it off. Works Ok with the Central Heating, just the water.
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Submitted: 2 years ago.
Category: UK Plumbing
Expert:  Andrew Smith replied 2 years ago.

If the pump and boiler are running on after the timer shuts down then there could be a problem with the motorised valve.

Follow where the power for the pump and boiler is coming from in the junction box in the airing cupboard

Customer: replied 2 years ago.
Hi Andrew. Im not sure on that. The water doesn't keep pumping, its the heater that keeps going. The gas boiler keeps re-igniting. It runs for 20, stops for 3-4 seconds, then starts up again. This keeps repeating, even though all the water in the tank is hot. Ive tried turning the temperature down on the controller, but it makes no difference.
Customer: replied 2 years ago.
Hi Andrew. Actually I have just fiddled about with the temperature gauge again, and all is working. What a numpty. Sorry to trouble you. Call the job complete. Thanks
Expert:  Andrew Smith replied 2 years ago.

No problem - keep an eye on it