Help with Under Sink Filter Plumbing

[Slicker]

Hi, I have a Mutilpure Aquaversa water filter that's attached to the cold-water line under my kitchen sink. The builder of our house plumbed the filter so that filtered water feeds a small sink faucet and my refrigerator. The faucet attached to the filter works fine, but the refrigerator has always had weak pressure/flow. I think this is probably due to the way the filter was attached to the refrigerator. The filter uses what looks like 1/4" plastic tubing with John Guest push connectors. The line to the refrigerator splits off a t-fitting and travels a good 10 feet before attaching to the original larger PEX tubing (1/2"?) that leads to the refrigerator. The builder cut out a section of the original PEX tubing, capped one end of the tubing, and used an adapter to attach the 1/4" tube from the filter to the other end. Everything was working OK until I recently had to replace the flexible line from the wall behind the refrigerator. I think the replacement line must be of a smaller diameter than the one we were using since ice has gotten very small and the interior water dispenser has very low flow (no flow if the sink faucet is being used). I've tried flushing the new line and a new fridge filter which only worked briefly before the flow slowed down again. So, in summary, I have a ~10-foot 1/4' line going to ~5 feet of 1/2" PEX, which then goes through a 1/4" compression fitting flexible line to the fridge. I've attached pictures to message of the setup I've tried to describe above.

Since the original set up didn't flow very well, I'm thinking the best solution is to just revert to the original set up and remove/plug off the 1/4" line coming from the under-sink filter, and reattach the 1/2" PEX line that leads to the refrigerator. I don't have tools to work on PEX, so I had a plumber come out to look at the setup and see if he could revert the system so that the under-sink filter feeds the faucet and the original PEX tubing feeds refrigerator. Unfortunately, he didn't want to work on the 1/4" coming from the under-sink filter, and only offered to remove the under-sink filter and reconnect the 1/2" PEX line in the basement.

This leads me back to trying to tackle this job myself. My plan was to get one of these 1/4" push on caps from Lowes (https://www.lowes.com/pd/SharkBite-1-4-in-Push-to-Connect-dia-Cap-Push-Fitting/100019257) and cap & cut the 1/4" from the filter to the PEX connection. Then I'd need to invest in some tools to cut out the adapter and cap on the PEX line in the basement, and crimp in a new section of PEX. I wanted to use SS crimp clamps (https://www.lowes.com/pd/SharkBite-...teel-PEX-Pinch-Clamp-Crimp-Fitting/1000182819) and this SharkBite crimp tool (https://www.lowes.com/pd/SharkBite-3-8-to-1-in-PEX-tool/1000224581).

After all that, am I on the right track here with my plan? Is this something a DIY'er can handle? Or should I try reaching out to a few other plumbers to see if they can handle the job for me?

 

[Terry]

Normally you would bring 1/2" to the kitchen sink. Does the frig have it's own filter? Mine does.
Small tubing and distance means a lot of friction loss. I noticed the cut and capped line in the photos. That didn't make any sense to me. And you're missing accessible shutoffs for everything.

 

[Sponsor]

 

[Slicker]

Sorry, in all that text I forgot to mention that this filter is running off the supply to the kitchen faucet and is feeding a separate drinking water faucet. It has a shut offs (in addition to the sink cold water shut off) and then there's a shut off valve behind the fridge. I've attached a picture showing the under sink connection. The plastic tubing from the t-fitting/valve leads to the filter and then to the drinking water faucet and refrigerator through the splice in the basement shown in the pictures above.

I don't know why the flow suddenly got so much worse with the new flexible supply line behind the fridge even after flushing the line and a new fridge filter (water is getting filtered twice). I checked at the hardware store today, and all the ice maker/fridge lines seem to be the same interior diameter, so I'm not sure what's happening.