Results 1 to 7 of 7
  1. #1
    Ive never had any problems with the closed loop system I have on two Premieres but noticed the pressure on the loops has dropped to virtually 0 while operating. The units have not given a "no flow" light or shut off but was wondering if this effects the efficiency of the units. Is this air or loss of fluid in line or both..

  2. #2
    Join Date
    Apr 2005
    Location
    NE PA
    Posts
    698
    The loop pressure will vary seasonally by 40-50 PSI. The actual amount depends on the antifreeze, the line length, any trapped air, etc. Normally the system is pressurized to a high enough pressure that it should not go below 10-15 PSI during peak cooling season. If it is a new system, the installer may have not pressurized it high enough. It could be as simple as adding some water to through the P-T fitting. The other possibility is that the system has a small leak somewhere and may have leaked down.

    Problem can occur if the loop gets below 10 PSI. The pump will be pulling against piuping losses and can start to cavitate, causing interruption in flow. This can result in a loss of system capacity and high refrigerant pressure. Most newer systems will detect the condition (Loss of flow fault you mentioned) and shut down. I would have the installer/service outfit come check it out.

    I always put a small 1 gallon bladder expansion tank in the system. With a tank, the loop pressure only varies about 5-6 degrees seasonally, and you can then operate at a lower loop pressure (I set it at 25 PSI). A bit easier on the fittings, etc.

    paul

  3. #3
    Join Date
    Jun 2006
    Location
    Lititz, PA (Lit' itz) not ( Li' titz)
    Posts
    122
    A leak is there! Problems I've seen: pumps get airlocked then unit shuts down on low water flow( high pressure on the ATV idiot lights, if in A/C) If the loop is piped in PVC I've seen the pumps air lock and heat up enough to start melting th pvc and then leaks start on the threaded fittings. and another popular problem is the antifreeze called GS4, highly corrosive teflon does not seal it. if there is an expansion tank they may develope a leak also.

    Either way you need a service call to find the leak and recirculate your loop.

    Happy day

  4. #4
    Does this low pressure have any effect on the efficiency of the system, will it cool or heat better depending on the pressure? thanks.

  5. #5
    Join Date
    Jun 2006
    Location
    Lititz, PA (Lit' itz) not ( Li' titz)
    Posts
    122
    It can if the gpm starts going down. the heat transfere will slow and effeicency will start going down

  6. #6
    Join Date
    Jul 2006
    Location
    Lancaster,Ohio
    Posts
    464
    Becuase there are so many reasons that a system may get air into the loop, from the water chemistry combined with the type and amount of anti freeze and the load, to mechanical seals in the pumps and valves to the type of loop the type piping and fastening method used, it is important to eliminate as many posibilities as you can. Remember this system, and this problem can suck the homeowners (and contractors) wallet empty. One of the biggest selling points of the system was the amount of money the homeowner will save..
    My godsend was the pressureless pump system. You can see the water level in the loop at a glance, The loop becomes self venting,It cuts down on the amount of equipment required to test and maintain the loop. It removes big bunch of guess work, and evaluating a lot of numbers.
    You can pipe it also to reverse the flow in the loop with the quarter turn of a ball valve!
    IcyFlame

  7. #7
    Join Date
    Apr 2005
    Location
    NE PA
    Posts
    698
    Originally posted by hotrodjohn
    Does this low pressure have any effect on the efficiency of the system, will it cool or heat better depending on the pressure? thanks.
    If the water flow drops, there is less water to carry the BTUs of heat, so the water temp in the heat exchanger will go higher. This requires more work out of the compressor, and lower efficiency.

    paul

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