Search the forum,

Discuss Potterton/Baxi Promax Ultra 40 - Fluctuating temp in the Central Heating Forum area at PlumbersForums.net

R

Renato

Hi,

I have the combi boiler Potterton/Baxi Promax Ultra 40.

When I set the temperature to (e.g.) 45°C, the boiler fire up and stay at max power until the hot water temp increases to 57°C and them it turn off the flame.
When the temperature reduces to 42°C, it fire up again.

Doesn't matter the setpoint of the temperature. If I set it to 55°C, it keeps on until the temperature reaches 67°C and them turn off. And turn on when the temperature drops to 52°C.

Instead of reducing the flame to keep the temperature stable around the set temperature, it keeps turning on & off.
It looks like it's at 100% or 0%. No middle term.

If I increase the water flow opening 2 taps on the same time, let's say the shower + sink tap, the boiler modulate normally and keep the temperature stable. When the temp is stable, I close the sink tap and the shower keeps stable for the whole time.

Anyone have an idea what I need to do to fix this annoying problem?

Thanks in advance!
 

Reply to Potterton/Baxi Promax Ultra 40 - Fluctuating temp in the Central Heating Forum area at PlumbersForums.net

Similar plumbing topics

Hi, Can anyone advise as to why the cold water to my bathroom keeps airlocking? This originally happened about 12 months ago and has happened 3-4 times since. It’s an upstairs bathroom, fed from a tank in the attic. The tank is about 8 Meters away and feeds a bath, sink and toilet. The tank...
Replies
9
Views
323
Creating content since 2001. Untold Media.

Newest Plumbing Threads

Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock