Pressure drop after cleaning filter

[Spindle]

I cleaned out the magnetic filter on my Worcester boiler for the first time and the pressure has dropped from about 1.7 bar to 1 bar. What could the reason be?

 

[Burger]

Seems to me like you’ve possibly lost some water from cleaning your filter.

 

[Riley]

Did you repressurise afterwards?

 

[Riley]

Also 1.7. Too high

 

[Rob Foster]

I cleaned out the magnetic filter on my Worcester boiler for the first time and the pressure has dropped from about 1.7 bar to 1 bar. What could the reason be?

Repressurise you system to 1.5 bar when cold....no more. Well done for cleaning out the filter most people dont bother and block their boiler up
centralheatking

 

[townfanjon]

Ignore above ^^^^^^

One bar

 

[sammathias]

I'd personally say 1.5bar.

 

[Riley]

I always say between 1-1.5

 

[Coby kenny AGUILAR]

You've cleaned the filter out whilst the boiler had been running, which is not a problem.

Sealed systems sit from 1 - 1.5 bar as per manufacturer.

When the system gets hot the pressure rises for example 1 bar to 1.7 bar.

When you have a day off, let the system cool and check the pressure then, make sure it's around the 1 - 1.5 bar mark, I personally keep it just over 1 bar as any tiny amount of excess air may vent out of an AAV and pull it below 1 bar.

 

[Rubin]

If you fill to 1.5 bar when cold when the heating circuit heats up it will be sitting around 2 bar, uneccsssary strain on all Pipework and joints. Better to fill to 1 bar so it’s around 1.5 when hot.

 

[Coby kenny AGUILAR]

If you fill to 1.5 bar when cold when the heating circuit heats up it will be sitting around 2 bar, uneccsssary strain on all Pipework and joints. Better to fill to 1 bar so it’s around 1.5 when hot.

I can see where your coming from but if your sealed system can't take 2 bar when hot, I'd suggest leaving a umbrella for when the diaphragm eventually perishes inside the expansion vessel

 

[Rubin]

I can see where your coming from but if your sealed system can't take 2 bar when hot, I'd suggest leaving a umbrella for when the diaphragm eventually perishes inside the expansion vessel[/QUOTL

Lool I’m not saying the system couldnt handle it , I’m saying why put excess pressure in the system when it’s not needed ?

Also like i said if you pressure to 1.5 bar and it gets to 2 bar when hot and over the year between services if the pressure in the expansion tank was to drop it will raise above two bar. Many engineers don’t check the level of pressure in the expansion tank when servicing.

 

[Coby kenny AGUILAR]

Lol I know that's why I said I can see where your coming from.

There's no right or wrong way if your between 1 - 1.5 but we all have our opinions and none of us are wrong

 

[townfanjon]

1.5 bar from cold , why ???????? When any boiler works on 1 .

 

[John.g]

The expansion vessel pre pressure is a very important setting as well, some are set at 1 bar and if the filling pressure is then 1.5 bar there will be a few litres of water reserve in the vessel while cold to make up any air venting and tiny leaks over time without the need for constant topping up, the pressure will then have to fall from 1.5 to 1.0 bar before this reserve is exhausted. If filling pressure is set to the same value as the pre pressure then this is not possible.
In general, I would suggest that the filling pressure should be 0.3/0.5 bar higher than the pre pressure.

 

[Coby kenny AGUILAR]

1.5 bar from cold , why ???????? When any boiler works on 1 .

1.5 bar from cold , why ???????? When any boiler works on 1 .

If you look at the dials it's not just green on 1 bar it has a range 1 to 1.5

I keep saying *between*

Yes any sealed system will work at bar, but as I said IMHO I go just over 1 bar because if you've drained it down to carry out work and refill system your not always going to get all the air out so when the aav opens to let out any excess air and its just one 1 bar there's a chance the pressure could drop under 1 bar and the boiler stops working because low pressure.

I'm guessing you've always filled to 1 bar and never had a problem, as I said we have our own way of doing things

 

[moonlight]

Internal expansion vessel is usually charged at .75 bar

 

[moonlight]

Internal expansion vessel is usually charged at .75 bar

 

[John.g]

Have seen pre (charge) pressures of 0.5 to 1.0 bar on externally mounted E.vessels, 0.5 bar should be the very minimum where the E.vessel (and boiler) is mounted on the ground floor as any lower setting than this will result in upstairs rads circulation eventually ceasing when the water reserve is used up.
Have attached a few numbers here showing the effect of three different pre charge pressures, all with +0.5 bar filling pressure.

 

[ShaunCorbs]

0.8 normally do mine too