combis/unvented running with no pressure

[traineedrip]

been doing a few rad jobs lately and found that the systems were very low or empty of pressure, customers totally unaware and heating seemimgly fine.

So what is the issue running like this? will it wear quicker? more stress on the pump?

 

[WHPES]

Would risk getting air drawn into system.

 

[fuzzy]

been doing a few rad jobs lately and found that the systems were very low or empty of pressure, customers totally unaware and heating seemimgly fine.

So what is the issue running like this? will it wear quicker? more stress on the pump?

what do you mean by combi/unvented? hot water is unvnted, a combi is a sealed heating system, i presume u refer to a combi. if the heating is working fine then whats the problem?

 

[traineedrip]

what do you mean by combi/unvented? hot water is unvnted, a combi is a sealed heating system, i presume u refer to a combi. if the heating is working fine then whats the problem?

I mean combis and sealed heating systems in general. They are supposed to stay pressurised at 1 bar cold. Customer info sheet says call out if pressure drops below .5 bar.

Would risk getting air drawn into system.

That makes sense, Thanks.

 

[Billy Bob Bob]

been doing a few rad jobs lately and found that the systems were very low or empty of pressure, customers totally unaware and heating seemimgly fine.

So what is the issue running like this? will it wear quicker? more stress on the pump?

pump damage,over heating mainly but lots will work at low pressure if it does not have a low water pressure switch,if its a diaphragm driven flow/pump pressure switch the pump could[and does]fail before the h/limit stat kicks in

 

[stevetheplumber]

most cobis and system boiler have a low water cut of nowadays most will work down to almost zero preasure

 

[fuzzy]

the only issue i have had with this is when a boiler is in the loft and the pressure drops below.5bar and keeps running the pump can burn out. pumps work better with pressure behing them(cannot remember why?) if they are at low level they should always have the head of pressure to support.
your right in saying the system needs to be topped up but ive had it when i could only get 0.5bar pressure and its still worked fine

 

[Bobdisk]

I am new to this, so please forgive ignorance. Recently the pressure in my Baxi HE130 system the CH pressure dropped to almost zero, but it still carried on ok. I recharged the pressure vessel to 1 bar, no water coming out of it, and the system to 1.5 bar. After a few days, it has settled to 1.6bar cold, and 2.6bar hot. (I have a more accurate second guage where I can see it as the boiler is in the loft) How does that sound for pressure, is that about normal?