Pulsating and repetitive sound from radiators when some thermostatic valves close

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mbagattini
mbagattini ✭
in General Questions & Topics

I have this problem that I would like to solve permanently.

All my radiators are equipped with a Tado thermostatic head. I don't have a Tado thermostat, just the headers.

The house is divided into three zones, each including several radiators.

It happens quite frequently that, when the cylinder heads close the valves, some radiators begin to emit a loud, repetitive pulsating sound, with a frequency of 1-4 pulsations per second.

The problem only happens on two specific radiators and is caused by the valve on those radiators not closing completely. I was able to recreate the problem by dismantling the Tado header and pushing the "pin" almost all the way in: at that point you can hear the pulsations both as a sound in the radiator and on the fingers pushing the pin.

I tried to move the adapter that connects the thermostatic head to the valve, without success: no adjustment is possible and the best I can do is tighten the head ring nut as much as possible, but even at the end of the stroke the closure is not sufficient.

The only way to stop the pulsation is to reset the system: from the Tado app, I set the area in question to off, then reset it. In this way you can hear all the valves in the area moving and the noise stops.

I love my Tado system but this issue is driving me crazy. My headers are first generation. If any other information is needed, please let me know. I partially translated this post with Google, as I didn't know some technical terms: please excuse me if something is a bit off.

Any help will be greatly appreciated!

Answers

  • policywonk
    policywonk ✭✭
    Options

    Not simple. These were the problems we had to address before the problem disappeared.

    1. Make sure the Tado thermostats are on the feed side.
    2. Make sure the pump pressure head is lowered enough to stop the hammering.
    3. Apply a powerflush - this removes all the blockages.
    4. Replace the CH pump with one that maintains a constant pressure differential, rather than a constant speed. It needs to be configured by a plumber who understands what this means, or you can read up about it for a day and get to the same conclusion.

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