Leaking Watts Bypass

FB

A seven year old Watts Pressure Differential Bypass valve is leaking. The leak occurs when the valve knob is opened more than half way, with some water dribbling out at the juncture of the knob and numbered ring. Watts does not sell a repair kit, has not heard of one leaking, advises that I can "tinker" with the valve, but it might need to be replaced. The system is full and running, so tinkering might be a water sport. Has anyone had experience repairing a leaking Watts #D4402050? Thanks for any guidance.

STEVEusaPA

Try to repair or replace, you're going to have to drain the system to do it...so you might as well replace.
Little odd to me if Watts said they never heard of one leaking that they wouldn't want yours back to investigate.
I'm sure you tried holding the knob and tightening the screw. Seems to me you could drain the system, remove the knob, and if there is some kind of packing, fix it.

Rich_49

How many zones in the system ? What type of emitters ?

FB

Thanks Rich and Steve for your replies. I am going to drain the system and take the valve apart, look for packing or maybe a torn O ring. The mechanical contractor who installed the system began with seven zones, so the bypass is connecting supply and return manifolds with seven actuators. The house is so small, this had to be his first attempt at design. When he had flow problems he couldn't sort out, he removed four of the seven thermostats and put actuator coils in parallel to control them with the remaining three thermostats. We have found that the system works best with the bypass slightly open. Emitters are six dandy Belgian radiators and about forty feet of radiant baseboard that isn't worth a darn. I added a radiator to the baseboard in the living room so we could get the space up to 68 degrees on a cold winter day.

Rich_49

A PDBV is most often used as a band aid for a poorly designed system or because someone was too frugal to purchase and install a variable speed pump . That being said , I'd bet you had this type of individual . Possible for you to send pictures of the radiant baseboard and the radiators ? There may be a simple , rather inexpensive real fix for your less than adequate heating system that struggles to maintain 68* on a very cold day .

icesailor

I think I went behind this guy. Long on theory and short on practical experience. So tight he creaks when he walked, but spent a fortune on a system that didn't work.