Water Pressure Gauge - Combination Boiler

[RaiderHammer]

I have a Saunier Duval THEMA F 23 E Combination boiler, it's about 8 years old. The water pressure gauge is nearly on the red markings 0.5 bar but when boiler fires the gauge goes to 1.5 bar.

1. Is this normal?

2. Does it need more water added?

3. Does this indicate there is air in the system?

Thank you for your help.

 

[mogget]

I have a Saunier Duval THEMA F 23 E Combination boiler, it's about 8 years old. The water pressure gauge is nearly on the red markings 0.5 bar but when boiler fires the gauge goes to 1.5 bar.

1. Is this normal?

Yes, it's quite a steep rise though.

2. Does it need more water added?

You should top it up to about 1.2 bar.

3. Does this indicate there is air in the system?

No.

 

[RaiderHammer]

I have a Saunier Duval THEMA F 23 E Combination boiler, it's about 8 years old. The water pressure gauge is nearly on the red markings 0.5 bar but when boiler fires the gauge goes to 1.5 bar.

1. Is this normal?

Yes, it's quite a steep rise though.

Is this anything to worry about?

2. Does it need more water added?

You should top it up to about 1.2 bar.

Even with the steep rise mentioned in point 1? If I top it up it may go to 2.5 bar when used?

Thank you for your help.

 

[mogget]

Even with the steep rise mentioned in point 1? If I top it up it may go to 2.5 bar when used?

Thank you for your help.

The steep rise can be caused by not enough air in the expansion vessel. However, to diagnose this problem you will need to fill it to 1 - 1.5 bar cold, and see what the pressure is when it's all heated up.

 

[RaiderHammer]

Even with the steep rise mentioned in point 1? If I top it up it may go to 2.5 bar when used?

Thank you for your help.

The steep rise can be caused by not enough air in the expansion vessel. However, to diagnose this problem you will need to fill it to 1 - 1.5 bar cold, and see what the pressure is when it's all heated up.

Thanks would this cause any weird sounds intermitently from the boiler like a sqealing noise?

If I fill up and it does go to 2.5 bar will this be a problem?

I am only a novice home owner!!!

 

[BingoBongo]

no dont fill it to 2.5 as when it expands on heating will lift the prv at 3 bar


do what the last 2 have told you and top up to 1.5

it may drop alittle when first put on as it displaces air

if you are hearing a squealing when filling it may just be the mains entering the boiler.which is ok

 

[Tipper]

no dont fill it to 2.5 as when it expands on heating will lift the prv at 3 bar

That's what the prv is for....to protect the system from overpressure!!!

(The only downside to lifting the pressure relief valve is that it may not reseat cleanly afterwards and may dribble forever more.

 

[BingoBongo]

no dont fill it to 2.5 as when it expands on heating will lift the prv at 3 bar

That's what the prv is for....to protect the system from overpressure!!!

(The only downside to lifting the pressure relief valve is that it may not reseat cleanly afterwards and may dribble forever more.

so you would advise people to top up pressure to 2.5 bar?????

 

[RaiderHammer]

no dont fill it to 2.5 as when it expands on heating will lift the prv at 3 bar


do what the last 2 have told you and top up to 1.5

it may drop alittle when first put on as it displaces air

if you are hearing a squealing when filling it may just be the mains entering the boiler.which is ok

Hi thank you. Sqealing noise is sometimes present when the boiler is firing up usually at the start, but not always it happens sometimes after it's been running a while. Seems to be present more when the weather is colder.

 

[Tipper]

no dont fill it to 2.5 as when it expands on heating will lift the prv at 3 bar

That's what the prv is for....to protect the system from overpressure!!!

(The only downside to lifting the pressure relief valve is that it may not reseat cleanly afterwards and may dribble forever more.

so you would advise people to top up pressure to 2.5 bar?????

No of course not. My point was that the boiler will protect itself against starting off with the pressure higher than the manufacturer wants, which generally seems to be about 1.5 bar. No need to be paranoid about starting with the pressure too high.