Boiler won’t refill, but pressure hasn’t dropped

[Kdi]

hi there

My boiler pressure is sitting at 1.25. However, hot water from taps is very weak. Tried refilling boiler, but I get nothing. I do have an external bladder. Cold water running into house fine. Overflow pipe has a large icicle hanging from it. Any ideas why the boiler won’t refill?

 

[Scott_D]

Post a picture

 

[Vee]

System pressure or mains pressure? Separate issues.

 

[Kdi]

System pressure

 

[Vee]

1.25 bar system pressure is absolutely fine for the boiler to opererate. Why are you trying to top it up?

 

[Kdi]

I’m not, but found it odd that the pressure to the taps is low, and no water flows when trying to fill.

 

[ShaunCorbs]

That pressure has nothing to do with your hot water pressure coming out of your taps

It's the pressure inside the radiators

 

[Kdi]

My boiler provides all hot water in the house.

 

[king of pipes]

Which boiler have you got is the filling loop built in ?under the boiler

 

[ShaunCorbs]

My boiler provides all hot water in the house.

Yes it's a combi boiler still doesn't alter the fact that the boiler pressure gauge is telling you the heating system pressure

 

[Kdi]

Filling loop is under boiler.

Problem isn’t with heating system but with hot water pressure, and the fact the filling loop doesn’t work.

Wonder if the bladder needs depressurised

 

[ShaunCorbs]

Sounds like there's a valve off before the filling loop somewhere

Don't touch the expansion vessel

 

[king of pipes]

Theres something partially open maybe ?

 

[Scott_D]

Tried topping up the pressure and closed the cold supply into the boiler

 

[Kdi]

Hot water is now working and filling loop is working. Weird. Anyway, thanks for all the suggestions.

 

[dan_the_plumber]

Supply pipe could have been partially frozen.
BTW...And it’s not a fantastic idea, but if you were to open the filling loop the pressure Guage on the boiler would show you the pressure you’ve got coming out of the ground.
You might not be able to get more than 1.25bar into heating system if you just haven’t got more mains pressure available.
In any case 1.25 bar is what your heating system should be set to

 

[Kdi]

Thanks Dan. Seems it may have been a frozen pipe. Filling loop does let the pressure rise higher than 1.25, but as you say, I'm happy to let it sit there. It was a particularly cold day when I posted.

Supply pipe could have been partially frozen.
BTW...And it’s not a fantastic idea, but if you were to open the filling loop the pressure Guage on the boiler would show you the pressure you’ve got coming out of the ground.
You might not be able to get more than 1.25bar into heating system if you just haven’t got more mains pressure available.
In any case 1.25 bar is what your heating system should be set to