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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Plumbing Questions >> Potterton Promax Ultra - Pressure https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1507047127 Message started by Sandy on Oct 3^rd, 2017, 5:12pm

Title: Potterton Promax Ultra - Pressure
Post by Sandy on Oct 3^rd, 2017, 5:12pm

Hi all,

I need to bleed a radiator in my CH system and may need to top up the water. The user guide I downloaded shows a way to establish the pressure either by a visible dial, or selecting an option on the digital readout. Heating hasn't been on for a few days, to the pressure is pretty static, however, the visual dial shows a pressure of approx 1.2/1.5bar, but when I checked the digital readout, it shows a pressure of 0.8 bar.

Which reading is likely to be more accurate?

thanks.

Title: Re: Potterton Promax Ultra - Pressure
Post by thescruff on Oct 3^rd, 2017, 6:21pm

You need to set it 1.2bar ish with the boiler and system cold.

Once you have turned it on the pressure will rise, an average 0.5-6bar, but depends on lots of variants.

What you don't want is the pressure heading much higher than 2-2.5 bar.

set the digital reading around a bar if you have problems, if the boiler is working ok, follow the visual dial

Title: Re: Potterton Promax Ultra - Pressure
Post by Sandy on Oct 3^rd, 2017, 6:35pm

Ok, thanks. Think I've got it.

Cheers.

Title: Re: Potterton Promax Ultra - Pressure
Post by thescruff on Oct 4^th, 2017, 8:34am

Just a quick thought Sandy.

Is the boiler higher than the visual gauge, say a floor lower, as 0.4 bar could indicate 4m height difference

Title: Re: Potterton Promax Ultra - Pressure
Post by Sandy on Oct 4^th, 2017, 11:53am

No. The dial gauge is housed within the boiler unit, right at the very bottom so lower than the rest of the unit by just a few inches, certainly not feet/metres.

When I've looked at the dial again last night, it's an odd scale. The scale doesn't read like 1.0, 1.1, 1.2 etc as you'd see on a usual "clock" type. 1 bar, 2 bar is represented by some colour coded scale that takes up a lot of the dial. It's not clear to read if the needle is at the lower end of 1 bar, or higher end.

I appreciate it doesn't make so much sense. I'll take a photo later and post it and you'll catch my drift.