I have a Richdel system which has worked fine until recently. I have one zone which when comes on has low pressure to the heads. All of the heads pop up but only puts out about 1/3 of the water. If you compress the first head in the run multiple times you can get the system "up to pressure and everything works fine. I have found no leaks, broken pipes, cracked risers etc. Could the diaphragm on the valve be bad? Any helpful tips would be appreciated.
