Watts Manifold

FB

Our GB142 heats the house during the cold months and supplies DHW all year. We lose about 2psi per month and have to add water through the backflow prevention valve for one or two seconds to compensate. Many hours have been spent inspecting pipes, Pex, fittings, rads, and boiler internals to no avail. Searching for the location of this slow but pesky pressure loss, we'd like to isolate one circuit at a time from our Watts Radiant manifold and monitor the pressure in the remaining system for a week or two during the warm months. We have the 3/4" BSP caps and gaskets to seal the two exposed manifold ports. To preserve as much of the treated system water, we wonder if there is a way to seal each end of the Pex connections we'll be removing? Referencing Watts' on line product catalogs, it appears that the female threaded caps that screw on to the manifold retain a cylindrical brass insert that seals inside the bore of the protruding male portion with an "O" ring. We'd appreciate any suggestions for somehow plugging each of these threaded-cap-and-insert ends to retain the water in the disconnected circuit. If plugging is not practical, could we use hose clamps to retain some sort of fabricated bladder around the ends? And any advice about what we might be overlooking (Spiro Vent, T&P valve, etc.) is appreciated.

hot_rod

Does the pressure ever drop to 0? Or does it just lose 2 psi and stay there?

What pressure are you running in the system?

Gordy

when are you checking the system pressure? System should be at ambient temperature.

Has this issue been a recent development, or since system was commissioned?

FB

Thanks for the replies. The same pressure loss has been occurring since the system was installed, all new, nine years ago. We keep the pressure between 20 and 30 PSI. The pressure will slowly drop over a couple months to the point that the display begins flashing the pressure display and will log a fault. I'm not sure what constitutes ambient temperature but the pressure does drop over time. Any advice about typical sources of pressure loss with a GB142 are appreciated. The heat exchanger is cleaned and inspected every year per the service manual.

hot_rod

Will it drop to 0 pressure after time? if so you have a leak, possibly in a loop. If it leaks a lot, like gallons at every refill, it more than likely is in a tube somewhere. You would see that much of a leak in the mechanical room.

Is this the manifold you have? Watts offers an iso-valve for the branch, buy some of those if you are wanting to test loop by loop disconnected from the manifold.

Some of the pex compression couplings, used for repairs, have that same type o-ring cone end, you could build your own plugs with some couplings, short piece of pex, and a crimp plug.

Caleffi part # 942550 may work, it is a nipple that fits the Caleffi manifold nuts. I'd be glad to send you one to try, it that is what you are after.





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