Search the forum,

Discuss question on water pressure in combi in the Plumbing Jobs | The Job-board area at PlumbersForums.net

Status
Not open for further replies.
W

wowthisistuff

Hi
My installer told me the optimum water pressure on guage of the worcester 38cdi boiler should be 1.25. However i see worcester say it should be 1.5, i wonder why the descrepnacy? Also i note that as the water temperture goes up in the central heating system the pressure rises to 1.8. Is this ok? This also leads me to the question of at what point should the pressure reading be taken, hot or cold? Is there actually an operating range to be observed? tx.
 
It'll be fine. WB make a recommendation based on lab conditions and a clean install. your guy is the man on site.
A rise of 4-6 bar as the system heats up is pretty much standard.

Have a nice evening, watch the box and don't be afraid to ask us again should you get any worries.
 
Last edited by a moderator:
At the back of the the boiler ,there is an expansion vessel,this takes care of some of the expansion of the water as the heating system heats up,the Worcetser use a min size expansion vessel,this is why on Worcester's we lowly engineers recommend at cold setting of 1 to 1.25,it just allows a bit more tolerance in the expansion ratio,if you are topping off at 1.8 bar when the system is fully up to tem,you could increase the cold setting a little to the 1,5 bar but no need and your engineer is correct in his advise to set around 1.25bar when cold
 
It'll be fine. WB make a recommendation based on lab conditions and a clean install. your guy is the man on site.
A rise of 4-6 bar as the system heats up is pretty much standard.

Have a nice evening, watch the box and don't be afraid to ask us again should you get any worries.

Did you mean a rise of .4 - 6 bar?
 
im curious then with the desired range being below too why the red doesnt start till over 3? what is happening in the 2-3 range that is undesirable but not enough of a problem to be showing as red in the guage?

thanks for the replies.
 
It'll be fine. WB make a recommendation based on lab conditions and a clean install. your guy is the man on site.
A rise of 4-6 bar as the system heats up is pretty much standard.

Have a nice evening, watch the box and don't be afraid to ask us again should you get any worries.

and at 3.5 bar your prv will work fine, dropping the pressure to zero. Dont worry about croppie, he is commercial, doesnt understand white goods :) ps a rise of 1.5 bar to 2.5 is about the norm, if your standing pressure is around 1 bar. you only need a higher standing pressure cold if your house is
over two stories
 
oh I thought commercial meant bigger pressures and stop checking out my rear :)

..... When you stop talking out of it......
evilbanana.gif
 
I useto use around 1/2 bar per floor

the amount of people that pump them up and up to try and increase there water pressure , lol

or over 3 bar then wonder why it goes to zero

the prvs never seem to reseal once they go , pumped a few expansion vessels up in my time but normally end up replacing them

did have a boiler that kept dropping and instead of replacing the faulty internal expansion vessel they had fitted another one in the loft ,
 
I would normally fill them up until I got water out of the highest point , as u only want to get the water to the top of the house , also due to low water pressure cut out switches I would normally put them around 1.5 bar ,

hopefully this is right , lol
 
Status
Not open for further replies.

Reply to question on water pressure in combi in the Plumbing Jobs | The Job-board area at PlumbersForums.net

Creating content since 2001. Untold Media.

OFFICIAL SPONSORS

OFFICIAL SPONSORS

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