I’m not a plumber! I want to understand how the turning of an automatic bypass valve knob is meant to work to determine if mine is weird.
Our actual plumber recently installed an auto bypass valve to our central heating system. Previously it had a gate valve.
He set up the bypass valve to setting 4.5 and said that, should the boiler overheat, I should open it by half a setting.
So, lo and behold the boiler overheated. It’s a Baxi Solo 3 PFL 80. Since the auto bypass valve was fitted, it overheats maybe once a day, when the pump is running after the thermostat has reached temp and turned the boiler flame off.
The bypass valve is just like one of these: https://www.toolstation.com/auto-bypass-valve/p28336
So I loosened the screw on the end of the bypass valve a bit, and turned the knob anti-clockwise a quarter of a turn. But the indicator didn’t move. I figured out that the black indicator numbers move about half unit every turn. OK.
To get a reference, I turned it anti-clockwise until it reached a stop. This was 7 full turns.
Question 1: I assume this is “fully open” - would that be right?
Question 2: I now turn it clockwise. Each full clockwise turn, there is a “click” (a spring-loaded twang). Is this normal?
Question 3 etc: I turn it clockwise until I get the indicator to 4.5. This is quite a lot of turns, say 8. But if I want to now turn it back anticlockwise, it hits a stop before it gets a full turn. Is this normal? Does it only “ratchet” one way? Why did it take 6-7 full turns anti-clockwise to get to a stop originally, and now won’t even turn anti-clockwise a single turn?
Thanks for help on this I’m sure it’s something really obvious.
Our actual plumber recently installed an auto bypass valve to our central heating system. Previously it had a gate valve.
He set up the bypass valve to setting 4.5 and said that, should the boiler overheat, I should open it by half a setting.
So, lo and behold the boiler overheated. It’s a Baxi Solo 3 PFL 80. Since the auto bypass valve was fitted, it overheats maybe once a day, when the pump is running after the thermostat has reached temp and turned the boiler flame off.
The bypass valve is just like one of these: https://www.toolstation.com/auto-bypass-valve/p28336
So I loosened the screw on the end of the bypass valve a bit, and turned the knob anti-clockwise a quarter of a turn. But the indicator didn’t move. I figured out that the black indicator numbers move about half unit every turn. OK.
To get a reference, I turned it anti-clockwise until it reached a stop. This was 7 full turns.
Question 1: I assume this is “fully open” - would that be right?
Question 2: I now turn it clockwise. Each full clockwise turn, there is a “click” (a spring-loaded twang). Is this normal?
Question 3 etc: I turn it clockwise until I get the indicator to 4.5. This is quite a lot of turns, say 8. But if I want to now turn it back anticlockwise, it hits a stop before it gets a full turn. Is this normal? Does it only “ratchet” one way? Why did it take 6-7 full turns anti-clockwise to get to a stop originally, and now won’t even turn anti-clockwise a single turn?
Thanks for help on this I’m sure it’s something really obvious.