I just finished DIY hydrojetting my kitchen sink drain line and before doing it I couldn’t find really any good walkthroughs, so thought I’d at least write my experience down. YMMV dramatically. I don’t really call people unless the government tells me I have to. HVAC people replaced my AC but I’ve added a sub panel, done supply and waste plumbing, and light construction. So this was on me to fix.
I have a branch drain line running under my kitchen and ending at my laundry room(https://i.imgur.com/QG9vnMc.jpg). A run of about 50 feet under a slab foundation. I was getting water backing up into my sink when the laundry washer would run then slowly drain. I tried to snake down both the laundry and the kitchen line but no luck. Laundry has a p trap I couldn’t get past and the snaking from the kitchen sink hadn’t seemed to help. I also tried a couple of chemical runs and still no luck. I saw hydrojetting was recommended for grease so thought it was the next thing to try.
I bought this sewer jetter set off Amazon but there are a lot of options like it. I hooked it up to my low power 1750 psi electric pressure washer(https://i.imgur.com/jsJd4u4.jpg) from harbor freight. I didn’t use the gun but just the switch to turn on and off the pressure. I used the head with a single forward jet and four reverse jets(https://i.imgur.com/R2IOD1k.jpg). I removed(broke) the kitchen sink drain line and just put the line down it(https://i.imgur.com/chOPppy.jpg). Pretty quickly after starting the pressure washer I started to get back flow from the line not draining quick enough. I used an oil filter and a few buckets to manage the flow(about 20 gallons).
I made pretty easy progress down the drain line unless there was an impediment. If it was a turn, just rotating the line and pushing forward was enough to make the transition. If it was a blockage in the line, it took some effort of rotating and pulling the line back about 6” and pushing forward. I hit my first blockage about 6 feet in and continued hitting blockages in places until I reached the main drain line about 45 feet in. As soon as I breached the last blockage at the main drain line the back flow stopped and the line cleared. I then went back and forth with the hydrojet along the length of the line trying to clear it out (blue line). Pulling the line out was easy and I didn’t get any significant snags.
Here are the additional things I learned or think other folks may want to think about.
I was comfortable I had relatively ok cast iron pipe. And have a good idea of the impact if there’s a break in the drain line.
If I was willing to spend a bit more money I would probably have bought and used a clog hog as the head is a little shorter and you might even be able to get through a 1 1/2” or 2” p trap. But it’s 3 times the price of what I used and it has no forward jet which I think ended up being important in my case. I’m glad I didn’t get it. As you would essentially have to push the head through any blockage.
I was fine with the lower psi on my pressure washer but I would have probably made more progress faster with more pressure. Though at maybe more of a risk to the cast iron.
Don’t under estimate the back flow. That’s probably the most difficult aspect of this. There’s a reason the want you to generally go from the low end up. So the water flow is helping you. If you’re going from the top down, you’re going to have to deal with the water a LOT more.
I heard once that if the line get snagged, and you can’t get it out. Like fishing, you’re going to have to cut and leave it. That sounds terrible. But maybe it’s an urban legend.
This can be done pretty easily on a 1 1/2” line if you’re past the traps. If you’re not… good luck.
I think the forward jet helped in my case because it pushed through the blockages and kept the crap going down the line.
I hope this helps someone. Best of success in all your plumbings.