I'm having strange problems with an OSO 20 hot water tank. We recently had the TPR valve and expansion valves changed for water loss from the tundish. Then we had an external expansion tank fitted as the hot water was initially flowing at extremely high pressure and temp and unstable. This was advised by OSO who said the air bubble was going.
The problem is now still similar. When turning on a hot tap we have a burst of extremely high pressure water. This lasts 10-15 secs and then drops and seems stable after. We have a pressure reducing valve fitted on the mains inflow to the house. This has a pressure gauge on it. I have noticed that as the hot water pressure builds, the gauge reads over 6 bar on the cold mains. Its usually 4 bar, reduced to 3 with the valve. This drops with the hot water being turned on.
Our plumber cant explain this. To me things are not right. The only thing I have noticed is that the hot tank pressure reducing valve is set to 0. I seem to remember it being 2+. (small blue dial)
The pressure in the expansion tank was 4.5 bar. Random check with hot water in there. It says it should be 3.5bar when cold. Could there be too little pressure in it.
Ant ideas?
Thanks for reading and in advance.
The problem is now still similar. When turning on a hot tap we have a burst of extremely high pressure water. This lasts 10-15 secs and then drops and seems stable after. We have a pressure reducing valve fitted on the mains inflow to the house. This has a pressure gauge on it. I have noticed that as the hot water pressure builds, the gauge reads over 6 bar on the cold mains. Its usually 4 bar, reduced to 3 with the valve. This drops with the hot water being turned on.
Our plumber cant explain this. To me things are not right. The only thing I have noticed is that the hot tank pressure reducing valve is set to 0. I seem to remember it being 2+. (small blue dial)
The pressure in the expansion tank was 4.5 bar. Random check with hot water in there. It says it should be 3.5bar when cold. Could there be too little pressure in it.
Ant ideas?
Thanks for reading and in advance.