Extremely noisy bedroom aircon unit - gurgling
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Joined: Mon Oct 23, 2023 8:42 pm

Extremely noisy bedroom aircon unit - gurgling

by EastAngle » Mon Oct 23, 2023 8:48 pm

Just over 4 years ago, we had a Daikin R32 split series unit installed in our bedroom and it has been under maintenance contract with them ever since.

As soon as we hit the first summer season, when the humidity climbed (meaning that there was lots of condensate for the unit to deal with) a problem appeared, and has continued to this day.

Initially, the complete system operated correctly. Every 10-15 minutes, a low noise could be heard from the (initially inline) pump, as it emptied the reservoir. It was almost inaudible.

However, as the season progressed, and heavier cooling was required, the system started to gurgle loudly, at first for short periods, then for longer and longer, and more frequently.

This was diagnosed as siphoning and various solutions were tried – a better anti-siphon valve was installed; the drop in the condensate outlet tube was shortened greatly to reduce the siphoning pressure; the in-line pump was replaced. None solved the problem.

Next ‘solution’ was to install a Gobi II external pump, with its own reservoir. This has two sensors, one sensor to start the pump when the reservoir becomes too full, and another to stop it before the reservoir is fully empty, to prevent it pumping air into the system.

Once again, this worked initially, almost silently emptying the reservoir every 10-15 minutes. But after a few weeks, it too started pumping when the reservoir was not nearly full, and continuing to pump air into the system far beyond the point where it should have stopped.

This pump was replaced with another Gobi II – and after functioning well for a few weeks it also started to operate almost continuously, loudly pumping air into the system, as if the ‘almost empty’ sensor was faulty.

This has become so bad that in order for us to get to sleep in the room during the summer, when the aircon is in operation, we have had to use a white noise generator to mask the extreme system gurgling.

It seems to me (not an air conditioning engineer but with a good technical understanding of electrical and mechanical systems) that the only common factor in these recurring problems is the Daikin room unit itself.

I assume that it has its own reservoir and its own ‘full’ and ‘almost empty’ sensors if it is to be able control an in-line pump without a reservoir.

Are the symptoms I describe consistent with any known misfunction in the wall unit, or of any incorrect setting or configuration … and if so, what?

I’m getting pretty desperate as almost 5 years on, this Daikin installation has not functioned as it should for a single summer.

Any/all suggestions are welcome!