Combi boiler pressure

[John.g]

The condensate test??
Will revert tomorrow, must go out now shortly.

What pressure is the boiler tripping out at??

 

[Alan ward]

The condensate test??
Will revert tomorrow, must go out now shortly.

What pressure is the boiler tripping out at??

Just below 0.5 I think . Have to check the book

 

[John.g]

So 0.5bar is 2 l? How do you calculate that?

A good question, I'm assuming that the precharge pressure is 0.5 bar, so a filling pressure of 1 bar gives a reserve of 2.0 litres, however, I did say losing up to 2 litres, obviously, if the precharge pressure is 0.75bar then loss is only 1.0 litre as the pressure will fall to the static head once the EV diaphragm is hard up against the water end, any further loss below 0.5bar would be far more worrying as you are then using the water from the upstairs rads as your reserve assuming EV downstairs.

 

[John.g]

Ok , can you tell me how to do that in steps please. I’ll try that next weekend
Thanks

As in post #5, you will have to identify the plastic condensate pipe and "break" it and measure any leakage but well after the boiler cools down, however I fear that it is like looking for a needle in a haystack at a leakage rate of say 1.5 litres/3 months = 0.69ml/hour or ~ 7ml in 10 hours.

You might be better off just now locating the boiler PRV (safety valve) waste pipe, it is generally a 1/2 ins copper pipe that might exit through a wall at the rear of the boiler and is turned inwards, when you do, tie a plastic bag around it and observe it for a few hours with boiler operating normally, this might just possibly be passing very slightly especially if the boiler pressure is reaching 2.5bar occasionally as you stated above. It is not shown in the above schematic but the condensate pipe is.

 

[Alan ward]

As in post #5, you will have to identify the plastic condensate pipe and "break" it and measure any leakage but well after the boiler cools down, however I fear that it is like looking for a needle in a haystack at a leakage rate of say 1.5 litres/3 months = 0.69ml/hour or ~ 7ml in 10 hours.
View attachment 73706
You might be better off just now locating the boiler PRV (safety valve) waste pipe, it is generally a 1/2 ins copper pipe that might exit through a wall at the rear of the boiler and is turned inwards, when you do, tie a plastic bag around it and observe it for a few hours with boiler operating normally, this might just possibly be passing very slightly especially if the boiler pressure is reaching 2.5bar occasionally as you stated above. It is not shown in the above schematic but the condensate pipe is.

As in post #5, you will have to identify the plastic condensate pipe and "break" it and measure any leakage but well after the boiler cools down, however I fear that it is like looking for a needle in a haystack at a leakage rate of say 1.5 litres/3 months = 0.69ml/hour or ~ 7ml in 10 hours.
View attachment 73706
You might be better off just now locating the boiler PRV (safety valve) waste pipe, it is generally a 1/2 ins copper pipe that might exit through a wall at the rear of the boiler and is turned inwards, when you do, tie a plastic bag around it and observe it for a few hours with boiler operating normally, this might just possibly be passing very slightly especially if the boiler pressure is reaching 2.5bar occasionally as you stated above. It is not shown in the above schematic but the condensate pipe is.

Ok

As in post #5, you will have to identify the plastic condensate pipe and "break" it and measure any leakage but well after the boiler cools down, however I fear that it is like looking for a needle in a haystack at a leakage rate of say 1.5 litres/3 months = 0.69ml/hour or ~ 7ml in 10 hours.
View attachment 73706
You might be better off just now locating the boiler PRV (safety valve) waste pipe, it is generally a 1/2 ins copper pipe that might exit through a wall at the rear of the boiler and is turned inwards, when you do, tie a plastic bag around it and observe it for a few hours with boiler operating normally, this might just possibly be passing very slightly especially if the boiler pressure is reaching 2.5bar occasionally as you stated above. It is not shown in the above schematic but the condensate pipe is.

As in post #5, you will have to identify the plastic condensate pipe and "break" it and measure any leakage but well after the boiler cools down, however I fear that it is like looking for a needle in a haystack at a leakage rate of say 1.5 litres/3 months = 0.69ml/hour or ~ 7ml in 10 hours.
View attachment 73706
You might be better off just now locating the boiler PRV (safety valve) waste pipe, it is generally a 1/2 ins copper pipe that might exit through a wall at the rear of the boiler and is turned inwards, when you do, tie a plastic bag around it and observe it for a few hours with boiler operating normally, this might just possibly be passing very slightly especially if the boiler pressure is reaching 2.5bar occasionally as you stated above. It is not shown in the above schematic but the condensate pipe is.

Thanks I will do the thing with the condenser pipe. I’m guessing I can just pull it out the boiler and put a bucket underneath.

 

[Alan ward]

Someone else has thrown a spanner in the works . Said the pressure vessel may not be able to handle the size of the new column rads we put it . To be fair with one of them is massive. Might be nothing and just information overload

 

[John.g]

Alan, that's a possibility all right but if so then the boiler PRV will lift and discharge water at 3bar pressure, you did say you have/had seen it at 2.5bar so you should do what I suggested above in my last post, for info a 8 litre EV will accomodate a system volume of 180 litres (quite alot) before reaching 2.8bar from pre/filling pressures of 0.75/1.0bar.

If the PRV has lifted a few times it could now be dribbling even at normal hot pressures of 2/2.5bar.