DHW Temperature Fluctuations on Baxi 105E

[andrewl41]

Hi All

Thanks in advance for taking the time to read this and (hopefully) respond!

I’ve had a problem with my Baxi 105 E for the last 6 months or so.

Basically, the hot water comes on perfectly and warms up quickly but after say 30 seconds to a minute it starts getting cold.

The boiler actually shuts off (as I guess it should once up to temperature) but seems to re-light again too late, once the temperature has already fallen well off.

You can see the temperature start to fall on the front, and it re-lights the second the reading starts to move down, but by that time the water is already cool coming out of the tap. It’s like it’s not seeing the temperature change quickly enough.

On some occasions, the boiler seems to work fine, say 20% of the time.

I’ve replaced the DHW temperature sensor, which had no affect. The Pressure Diff assembly is also only 12 months old, and is working fine as well from what I can see visually.

I can’t believe it’s the heat exchanger, as I’d have thought this would stop working consistently and would fail to come up to temperature properly at all, but I may be wrong.

Anyone know what this may be?

Thanks

Andrew

 

[popeye2755]

Check this:

//www.diynot.com/forums/viewtopic.php?t=246313

 

[andrewl41]

Hi popeye2755

Thanks for the response. The thread seems to describe my problem perfectly and just as importantly, the explanation makes sense.

I'd searched but only for 105 problems, I should have looked for related models too.

Thanks again

Andrew