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Possible e x v not opening

I have a Fijitsu unit with 4 heads , every day for like 6 hours, usually when sun is strong on the condenser the air isn’t working. Let me explain …….
I have 2 - 1 ton air handlers and a 7,000 btu air handler……. Every day in afternoon the rooms get to 72 although I have the remotes set at 68.
When it was 72 last it in house ad it was 78 outside the remote was set to 68 there was no sweating on 3 of the 4 line sets outside. To throw a monkey wrench in the mix, the insulation on the line set rotted away, I’ll put some insulation on Monday or Tuesday.

The questions are can the EXV valves fail, or do you think the line set not being covered for 12 inches give the pressure some odd reading where they’re not opening?

Comments

  • ratio
    ratio Member Posts: 3,777
    Well, yes EXVs can fail; and no, a foot of missing insulation isn't going to noticable effect operation. However, there should be one EXV per port on the condenser. The odds of them all having synchronized individual failures is …not probable. More diagnostics are needed. I might start with a manifold on the service teats during the transition from a working period to a non-working period.

    Are any error codes displayed/blinked?

    mattmia2
  • pecmsg
    pecmsg Member Posts: 5,271
    Forget gauging up. 
    You need a trained tech on site!
    GGross
  • Snowmelt
    Snowmelt Member Posts: 1,425
    No codes on indoor unit, outdoor I didn’t take cover off. Only possible leak is threw the copper ……..
    the tricky thing was it was on all day, it was fine till 4 pm temp was 68 in house. At 10 pm it climbed up to 72. I went outside to see if unit was frozen. Three lines were outdoor temp no frost or sweat. I felt the lines for 5 minutes I swear I heard the fan ramp at different speeds, I went inside 1/2 hour later it was comming out cooler and within three hours the whole house was do2n to 68
  • HVACNUT
    HVACNUT Member Posts: 6,282
    It's low on refrigerant. Repair the leak(s).
    And you said 4 heads but only mentioned 2- 12's and a 7.
  • pecmsg
    pecmsg Member Posts: 5,271
    edited August 2023
    Only possible leak is through the copper?
    what about the condenser coil, evaporator coil, the 6 or eight flair nuts, any number of the thousands of brazed joints in and around the system!
    GGross
  • Snowmelt
    Snowmelt Member Posts: 1,425
    K I’ll check for leaks again. The 4th unit is a 9,000 btu ceiling cassette , which is operating fine
  • pecmsg
    pecmsg Member Posts: 5,271
    Snowmelt said:
    K I’ll check for leaks again. The 4th unit is a 9,000 btu ceiling cassette , which is operating fine
    The 1st thing is to pull and weigh the charge. Than you’ll know if there IS a leak!
    GGross
  • Snowmelt
    Snowmelt Member Posts: 1,425
    Thanks Pec , I do have a statement , also asking for your thought. The 4th head is a ceiling mount which has no ducts . I just called my wife she’s home right now . She told me she gave the unit a rest for 2 hours , it reached 75 in the house . The one room which is a ceiling cassette (no ducts) cooled the room to 70 degrees in 2 hours. Which in just blowing my mind. Now my attic is very hot. I’m thinking the little bit of duct work is not insulated enough , I’m going to have to get a temp at the inside coil also, I thik
  • ChrisJ
    ChrisJ Member Posts: 16,260
    No sweating on which lines, specifically?

    If there's four heads that's 8 lines. On a minisplit all 8 of those lines should be cold if the heads are running, four of them extremely cold as they're coming out from the EXV's, no?


    If both lines going to a specific head aren't sweating, I'd say there's a big issue there and it's not the lack of insulation.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Snowmelt
    Snowmelt Member Posts: 1,425
    Thanks all, I’m on top of it , I’ll let you know all what happens