I have a Viessmann Vitodens 100-W that heats my house, and I presume delivers hot water too.
I must confess I have been negligent, and never had it serviced. The unit is 8 years old. I will get it serviced soon,provided I can find a licensed service mechanic for it.
Now, I did notice that the pressure gauge reads 13psi, which is pretty much the minimum level according to the manual (the manual does contradict itself by first stating the minimum is 12psi, and later in the text it says 14psi.)
The procedure is not listed in the owners-manual, but is it something that a homeowner could do, add water to increase the pressure?
Is it just a matter of opening a valve somewhere until the pressure gauge shows the correct value, or do I actually have to hook it up to a gardenhose?
UPDATE: Thanks George, I have found something called "Backflow Preventer."
It seems to have a valve both in front and after it? Or is it some sort of other lever, that I see to the left of it?
I am in Canada.
Best Answer
Lift the lever on top of the pressure regulator briefly, that should allow water to flow in, and raise the pressure.
On most systems, the inlet valve is left closed except for maintenance - they should not normally leak, so they should not need constant refilling. Your inlet valve appears to be open as pictured.