NTI trx150c error 108

qquser

Hi, dear folks: my NTI TRX150c combi water pressure drops down to low psi(5.8) when using hot water after couple people take shower or use hot water for a certain time. I checked all radiators and pipes, I don’t find any leaks. When the heat is turned on, the water psi is usually around 23.2psi which looks normal. And can I manually set the PSI to be at 12 psi by adjusting the watts feed pressure regulator so it will always come back to 12 psi ? I can just turn the adjustment screw to set the psi I want when the boiler is not running?

Tom_133

I dont install TRX boilers, but I do install many NTI's. What I have found with these combi's and many others are that the system needs to be set for 20 PSI. I do this by making sure the expansion tank is set for 20 PSI before I install it, and my feeder is set for 20 PSI. Something about the way the diverter internally works makes this necessary. You cant always go by the gauge on the supply pipe since that is seeing the PSI from the circulator. Im assuming the TRX has a digital on the screen

qquser

thanks for your reply. Their instruction suggests 12-15 psi for expansion tank. I will try to add more pressure when I get the test gauge

qquser

https://forum.heatinghelp.com/discussion/comment/1875478#Comment_1875478

Thanks for your reply. Their instruction suggests 12-15 psi for expansion tank with this combi. I will try to add more pressure when I get the test gauge. It has a screen shows the psi, but the psi on screen never matches the one shows on water pressure gauge meter.

Tom_133

they say it in other instructions and yet when u call tech support they ask you to set it for 20!

It may not be your problem, but I have seen it fix a few similar ones! Hope it goes well for you.