Turning the boiler back on?

[HandFoot]

Hello,

We have a Main Combi 24HE in our place.
Last night, my radiator valve started leaking, I've turned off the water supply to that exact radiator, turned off the central heating function (only the function, not the actual pipe) on the boiler and decided to look whats wrong with the valve. I've unscrewed the valve and there still was some pressure left in the system so I've put it back on because it started leaking water very badly. Then I went to the boiler and turned off the valve of the first pipe from the left (I assumed that this one was the one because it was warm and it looked like it was going towards the radiators). Today I got a new valve, had a lot of water run out of the radiator, but I successfully changed it. I've turned the water supply to that exact radiator back on, turned on the valve underneath the boiler back on (the first one from the left), and turned the boiler back on to central heating + hot water function and I saw a Burner Failure LED light up, and heard water filling up (or dripping) inside the boiler, I thought the burner will work again when it's filled up but after some time my wife heard a quite sound which reminded her of an elephant and the sound suddenly started getting louder until even I heard in the other side of the house, I quickly ran up to the boiler and turned it off and then turned the hot water only function back on after some time.
The water from the taps is cold and when you open the tap I see a Burner Failure LED and I hear water filling the boiler.

The system has received a lot of air while I was changing the valve, maybe that's the problem?

Please give any tips because our landlord is away for two weeks, and 2 weeks without hot water is hell....

Thank you.

 

[seco services]

you haven't said that you refilled the system after draining to do the valve.

 

[HandFoot]

I haven't. I've never had any problems before with a boiler, so this is the first time I'm actually doing something with it (except turning the heating up).

I know where the tap is which fills up the boiler, but how do I know when to stop filling it up? Look at the pressure gauge?

More information about the sound:
I've turned the boiler on and waited for about 5 minutes, at all times I've been hearing water willing up or something, then after some time I've heard something like snoring (not constant sound, it appears once 2 seconds for a second or something like that), it got louder and louder and then another sound appear which sounded like a power station or something which was constant and then everything got louder and louder.

 

[seco services]

whats the gauge reading ?

 

[HandFoot]

0 at all times, no matter if the boiler is making sound or he isn't. No matter if its turned on or off.

Will the gauge show pressure if the boiler is turned off?

The fact that the system is not filled up could cause that sound, and the burner failure?

 

[seco services]

turn the boiler off and fill the system to about 1 - 1.5 bar.
you'll probably have to bleed the rads after refilling.
but keep checking the gauge while bleeding.
flashing burner led is overheating.

 

[HandFoot]

Woohoo... The burner LED is on and everything seems to work after this tip. I will bleed the rads later when the system heats up.

 

[HandFoot]

Thank you

 

[gas4you]

You ideally always bleed rads when the system is off and cold

 

[seco services]

bleed the rads with the boiler off.
keep eye on the gauge as it will drop while bleeding the rads.

then just top it up to about 1 - 1.5 bar again.

 

[HandFoot]

1.5Bar without bleeding, when I open the tap the pressure gets to 2Bar, is that okay?

Okay, the pressure is getting a bit higher, I don't think there is a easy way to remove the water from the system?

 

[HandFoot]

You ideally always bleed rads when the system is off and cold

It's not so cold at the moment, I could live without heating at all, the main point was to get the hot water back

 

[seco services]

your pressure will rise slightly as the water gets hot and expands.

 

[HandFoot]

From 1.5 to 2.0Bar right now... Does cold water expand by 33% when it gets hot? 2.5Bar when I open a sink tap. The gauge shows up to 4Bars so until its not something like 3.5 Bars its okay? How do I remove some water just in case? Is there a clean way of doing that? Because I'm not looking forward into having more puddles somewhere around