Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 5 of 5

Thread: Restricted filter

  1. Back To Top    #1

    Restricted filter

    Hi all. I am having a problem with my filter pressure.My pressure is generally about 18 - 20. I went out tonight and backwashed (pump was off) and the pressure shot up to 50 and blew my backwash lines apart. I thought maybe I had a restriction in my backwash line so I switched back to filter and turned the pump back on and the pressure shot up just as high. So then I tried waste, pressure still high but maybe only 40. Then I tried recirculate. Pressure still high (around 40) but a little water was coming out my backwash line. I let it run for a minute thinking there was just a little pressure releasing but it continued. So now I basically have high pressure on all filter settings. I think the backwash initiated the problem.

    Now, the rest of the story.... We had a freak cold snap with a hard freeze for an extended period here in oklahoma last month. The lows reached the teens with highs in the 20s for about a week. In general the winters are pretty mild and freeze timers do the trick (This is our second winter with the pool and left it open last year with freeze timer and no problems). I did go out and drape canvas and tarps over the filter and pump and placed 350 watts of halogen light in there during the coldest weather. While the pool froze over the pump continued to run just fine with reasonable pressures as I checked it daily. It is now reaching into the high 50s (sometimes 60s) daily with lows in the upper 30s and everything has completely thawed.

    Sorry for the long post but it's supposed to get down to 29 this weekend and am hoping I can resolve this before then as I am leaving my pump off for now. Thanks in advance.
    25K plaster, 1 HP Hayward TriStar, 31" sand filter, Mastertemp 400K HD heater, Compupool 40K SWG, peristaltic acid pump, DIY Arduino/Linux Automation, Nitro Wall Scrubber robot

  2. Back To Top    #2

    Join Date
    Mar 2007
    Location
    Coastalish 'down easter'
    Posts
    4,160

    Re: Restricted filter

    Welcome to TFP!!

    It sounds like you're doing things correctly

    Are you sure that the pressure gauge is still good?

    It also sounds like your multiport was damaged in the cold snap Probably it was just the gasket inside. I would plug the waste port and ask (or use the search function) about it
    Luv& Luk
    -Ted

    Having done construction and service for 4 pool companies in 4 states starting in 1988, what I know about pools could fill a couple of books - what I don't know could fill a couple of libraries :-D

    POOL SCHOOL, TF Testkits, Jason's Pool Calculator, CYA vs. cl chart, (Just a few DARNED handy links!)

  3. Back To Top    #3

    Re: Restricted filter

    Thanks. I think the gauge is bad. After a few on/off cycles I noticed it hanging a few times and not dropping to zero and giving bad readings.

    I moved the multiport a few more times trying to diagnose and heard a loud cracking sound and now the handle feels different when I depress and rotate. So I'm now guessing you are correct that the multiport valve is bad.

    Thanks again.
    25K plaster, 1 HP Hayward TriStar, 31" sand filter, Mastertemp 400K HD heater, Compupool 40K SWG, peristaltic acid pump, DIY Arduino/Linux Automation, Nitro Wall Scrubber robot

  4. Back To Top    #4

    In the Industry

    Join Date
    Jan 2010
    Posts
    7

    Re: Restricted filter

    A sharp increase in pressure is usually related to a blockage in the return line or even the filter. If it had been a while since your last filter clean/backwash, your guage may just be clogged or dirty. This would also explain why when you kicked on the pump the psi shot up so high. If there was part of your backwash line restricted(ice, excess debris) coupled with high filter pressure that can explain the busted backwas line.
    Sounds like the multiport is broken, which may be the sole cause of the pressure issue, hopefully.
    You'll want to check for any leaks in the plumbing while your service guy is out to capitalize on the service call fee. Leaks that freeze cause blockages. One service fee($80-100/hour) is better than two right?
    Manually cleaning a filter is not that difficult and may not be necessary, but if your filter is clogged, that can be the entire problem in and of itself. There are a couple of good you-tube vid.s that provide great visual aids. Make sure you mark the position of the top and bottom shells before you take them apart! I say this to maybe considering having the service company manually cleaning your filter(avg. $135) as there may be a discount involved doing this at the same time as replacing your multiport.
    Pressure that high for any significant amount of time can cause damage to filter elements, so prepare yourself for repairs there as well(sorry dude ).

    Sorry for the lengthy response but w/o seeing the pool in action it is hard to tell. hope this helped!
    7600 gal, IG rectangular, SWG wood-fired pool heater, solar heating (pool not too warm, hot tub too big)

  5. Back To Top    #5

    In the Industry

    Join Date
    Jan 2010
    Posts
    7

    Re: Restricted filter

    Also, if it freezes and you can't fix the pressue issue or multiport in time, recirculate mode will run most of the plumbing and thereby protect the majority of the plumbing and minimize damage, only as a last resort.
    Good luck!
    7600 gal, IG rectangular, SWG wood-fired pool heater, solar heating (pool not too warm, hot tub too big)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •