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canuck the pro
canuck the pro, Plumber
Category: Plumbing
Satisfied Customers: 2864
Experience:  Plumber and Handyman
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Hi I have been looking at a problem with TV interference that

Customer Question

Hi I have been looking at a problem with TV interference that I've tracked down to the motorised valve in the hot water system, the valve operation is the question. Firstly make and model :Danfoss HSA3
When the hot water tank calls for the system to supply water the valve operates, gets 7/8th of the way there then stops and sits there clicking (approx once a second), during this action the TV is disrupted. This continues until the hot water request is cancelled whereupon the valve then completes it's arc of travel all the way in the same direction. The clicking obviously stops and the TV signal returns to normal.
I presume this 7\8th travel then stop then the final fraction completing is the problem and not a function of the switch and would like some confirmation of this before I go and purchase a replacement unit.
Submitted: 3 years ago.
Category: Plumbing
Expert:  canuck the pro replied 3 years ago.

canuck the pro :

Hi, my name is XXXXX XXXXX I have been in the plumbing and plumbing repair field for 20 years. I will be glad to help you today. If you remove the motorized part the port valve is likely sticking. If you can free it with a little silicone spray then it will be all well. If it is not the port valve then the motorized valve will need replacing.


This clicking and sticking occurs with the motorised unit removed from the valve, so no valve sticking. So you're saying the motorised valve should complete full travel, and this funny whereby it completes it's full travel only when the heating request is cancelled? What changes inside the mech. when that happens, I'm an electrical engineer, I have a need to know when it comes to these things, I blame my father.

canuck the pro :

Inspect it while removed and you can very likely silicone spray the moving part in the motorized valve. The microswitch is likely the culprit.


OK, it needs torx drivers to get to, this at my parents, I'm travelling home today but coming back next week, must remember to bring them, I'll give it a try, if it doesn't work I'll go for a replacement, thanks for the support.

canuck the pro and other Plumbing Specialists are ready to help you
Expert:  canuck the pro replied 3 years ago.
You are very welcome.

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