Question about Bar pressure related to black and red dial!

barni2006 Sat Jun 15, 2013 10:24 am

Dear All

I have always used filling loop to top of pressure of pressure gauge next Boiler Mate to either 1 or 2 (black dial). What is the red dial pressure for. what value this needs to be and how do we change it? I think the cold water pressure used to be pretty good in my shower but think its not that good any more, not sure if I am wrong. I have no complain about hot water pressure though. The Red Dial pressure currently in my home is about 1.7, does this need to be between 3 & 4. Please advise. Any comments from other members would be great!

thanks

Mario.S Sun Jun 16, 2013 1:07 am

If you talking about the red needle on the dial, this is only a marker to remind you of the required pressure, the black needle is the pressure in your system. this red one can be manipulated with a screwdriver to match the black required 1 bar at a cold system and indicates if the pressure is going up or down.
Hope this helps

Mario at Mario's Boiler Service

barni2006 Sun Jun 16, 2013 3:38 am

many thanks for your help Mario:-) Would you know if pressure should be more while keeping the temperature know towards cold water as I suspect this to be the case which not happening anymore!

thanks again

Mario.S Mon Jun 17, 2013 1:58 am

barni2006 wrote:many thanks for your help Mario:-) Would you know if pressure should be more while keeping the temperature know towards cold water as I suspect this to be the case which not happening anymore!

thanks again

Domestic central heating systems are filled when cold with 1 bar and of course if the system water getting heated, the water ( as any liquid) will expand. Depending on the volume of the system ( cylinder water plus all radiator and pipe water) the expansion can rise the system pressure up to about 2 bar. For system safety , the required over pressure release valve is discharging any pressure above 3 bar. Is your pressure dropping all time, means you have a leak in this system. Is your pressure permanently rising higher than 3 bar, means your expansion vessel ( the Wight or red cylinder, connected to this sealed system) is flat or faulty and the system water has no space for expanding .Expansion vessel contain an rubber balloon filled with air ,matching the system pressure when cold and getting compressed from the system liquid ( system water)course gasses are compressible , liquids are not. To monitor and diagnose those faults, the red "Marker" on your pressure indicator is fitted.
I hope this is not to technical
Mario at Mario's Boiler Service

barni2006 Tue Jun 18, 2013 1:30 pm

Hi Mario

many thanks for your detailed explanation. No, the pressure doesn't drop. So that is not a problem. Only issue which may be a non issue that shower pressure with cold water is not that great as it used to be and I was wondering what could be the problem. However the shower pressure with mix of hot and cold water is perfectly okay.

thanks again

barni2006

Mario.S Thu Jun 20, 2013 1:03 am

The cold water pressure is not influenced from your Boiler at all, this is coming direct from the main supply. There could be a problem with your Tap ( blocked partly, lime scale...) or pipe work ( if this is on all the cold outlets). The water pressure to your house seams ok, course your hot water is running ok (also feed direct from you cold water to the boiler)
Regards

Mario at Mario's Boiler Service

barni2006 Fri Jun 21, 2013 10:15 am

thanks for your help Mario. It makes sense now!

Sponsored content

Question about Bar pressure related to black and red dial!

Question about Bar pressure related to black and red dial!

Re: Question about Bar pressure related to black and red dial!

thanks

Re: Question about Bar pressure related to black and red dial!

thanks for your reply

Re: Question about Bar pressure related to black and red dial!

thanks for your help

Re: Question about Bar pressure related to black and red dial!