Hello!
My mother has a house from '64, with a water-based system on both the lower and upper floors.
This is heated with an old electric boiler. There's some kind of expansion tank, about 12L.
My brother has been living in the house since last winter, and through him, we've had some correspondence when it's been too cold/too warm.
Recently, he discovered that the boiler was running a bit too hot (about 55-60 degrees) and the return temperature was around 35.
The pressure was then at 0.9 Bar.
I tested the air vent under the expansion tank and only air came out, no water.
We turned off the boiler as a result, and while the circuit cooled down, the pressure dropped further to 0.2 Bar.
I've tried to troubleshoot as best as possible, and I didn't make any changes other than refilling the circuit to 1.0 Bar again, turned on the boiler, and now after 2 days, the pressure has dropped to 0.6 Bar again.
The boiler heats really well, about 50 degrees at the outlet.
I wonder what you think the problem might be?
I replaced a safety valve (1.0 Bar) last winter on an old geothermal heat pump out in the garage, which is connected to the same circuit. I replaced it because it was leaking. Not a lot, but a little.
Could it possibly be that the safety valve on the expansion tank is faulty and needs replacing as well?
If so, I know how, with flax and pipe paste.
But... as I understand it, a little water has leaked from the expansion tank but not in large amounts - Could that really be it?
Thanks
/Meads
My mother has a house from '64, with a water-based system on both the lower and upper floors.
This is heated with an old electric boiler. There's some kind of expansion tank, about 12L.
My brother has been living in the house since last winter, and through him, we've had some correspondence when it's been too cold/too warm.
Recently, he discovered that the boiler was running a bit too hot (about 55-60 degrees) and the return temperature was around 35.
The pressure was then at 0.9 Bar.
I tested the air vent under the expansion tank and only air came out, no water.
We turned off the boiler as a result, and while the circuit cooled down, the pressure dropped further to 0.2 Bar.
I've tried to troubleshoot as best as possible, and I didn't make any changes other than refilling the circuit to 1.0 Bar again, turned on the boiler, and now after 2 days, the pressure has dropped to 0.6 Bar again.
The boiler heats really well, about 50 degrees at the outlet.
I wonder what you think the problem might be?
I replaced a safety valve (1.0 Bar) last winter on an old geothermal heat pump out in the garage, which is connected to the same circuit. I replaced it because it was leaking. Not a lot, but a little.
Could it possibly be that the safety valve on the expansion tank is faulty and needs replacing as well?
If so, I know how, with flax and pipe paste.
But... as I understand it, a little water has leaked from the expansion tank but not in large amounts - Could that really be it?
Thanks
/Meads
Start by placing something under the outlet of the exp valve. That way you can see if it's leaking.
When you're measuring the pressure, is the circulation pump turned on?
It might also be good to check the pre-charge on the vessel before you start looking for deeper faults in the system.
When you're measuring the pressure, is the circulation pump turned on?
It might also be good to check the pre-charge on the vessel before you start looking for deeper faults in the system.
Interesting.C cap said:
Does it matter whether the circ. pump is off or on, do you mean? Why?
The circulation pump is built into the electric boiler and turns on/off when the boiler is on/off.
So to answer the question, I measure the pressure on the manometer, which is both built into the electric boiler and has an extra on the expansion vessel above if I want to double-check.
I've measured the pressure with the boiler (and circ pump) turned on.
Sincerely,
/meads
The reason for the question is if the manometer is connected to the return, the pump can lower the pressure when you have such low pressures and no temp. Or conversely, if many thermostats are closed and the manometer is on the pressure side, the pressure increases and then decreases if the thermostats open. Normally, you should always measure with the circulation pump turned off to ensure you see the static pressure and not the dynamic one.