Air in heating circuit.

Steve

What can cause air to get into a heating system?

It's a sealed / pressurised circuit with an expansion / pressure / air bladder that has about 1 bar pressure measured.

Not mine but asking on behalf of a friend.

Symptoms are apparent low flow through the boiler (gas condenser) which results on an over temp lockout. Pump has been checked and is ok, 3 zone valves which have been checked and are working ok. It can work fine for a few weeks and then fill up with air again to the point where the pump can't get flow through the boiler and system locks out again and needs to be bled.

Any pointers?

Wearb

Steve wrote: »

What can cause air to get into a heating system?

It's a sealed / pressurised circuit with an expansion / pressure / air bladder that has about 1 bar pressure measured.

Not mine but asking on behalf of a friend.

Symptoms are apparent low flow through the boiler (gas condenser) which results on an over temp lockout. Pump has been checked and is ok, 3 zone valves which have been checked and are working ok. It can work fine for a few weeks and then fill up with air again to the point where the pump can't get flow through the boiler and system locks out again and needs to be bled.

Any pointers?

Is there an auto water top up or do you have to connect a loop and manually top up the pressure after bleeding?

Steve

Wearb wrote: »

Is there an auto water top up or do you have to connect a loop and manually top up the pressure after bleeding?

Top-up is done manually via a valve connected to mains pressure which is then closed afterwards.

K.Flyer

Steve wrote: »

Top-up is done manually via a valve connected to mains pressure which is then closed afterwards.

How often?

Wearb

Steve wrote: »

Top-up is done manually via a valve connected to mains pressure which is then closed afterwards.

Is there a removable flexible pipe that you can check to see that the mains supply is fully being turned off?

Wearb

Btw answer your op; “air” is usually caused by fresh oxygenated water getting into the system and reacting with the system metals to produce gas.

The Mulk

Steve wrote: »

Top-up is done manually via a valve connected to mains pressure which is then closed afterwards.

Could a small leak be causing the problem?

Bruthal

How often is water being added?

septictank

Sorry for Hi Jack, same problem here, manually topped up 1/2 times a week, Loud bang this morning, thought it had blown, off now.

Would a propper boiler service engineer fix this or much bigger job?

Baxi boiler 10 years old.

Wearb

septictank wrote: »

Sorry for Hi Jack, same problem here, manually topped up 1/2 times a week, Loud bang this morning, thought it had blown, off now.

Would a propper boiler service engineer fix this or much bigger job?

Baxi boiler 10 years old.

You would need to ask if service tech would do it. Would mostly be a plumbing job.

Steve

Bruthal wrote: »

How often is water being added?

It works fine for 2-3 weeks at a time and then lockout happens. I've recommended he get a pro to look at it but, well, he's an engineer and would like to understand the cause and be able to fix it himself... (:))

wiz569

Steve wrote: »

It works fine for 2-3 weeks at a time and then lockout happens. I've recommended he get a pro to look at it but, well, he's an engineer and would like to understand the cause and be able to fix it himself... (:))

He has a leak somewhere,best get it fixed