Corrosion and scale in unit

[fetch]

So as stated in my introduction post, I recently purchased a used Alkota 320x4 pressure washer. When I did the trial run, I was very disappointed. I packed it up, and stored it for the winter. Its finally starting to thaw up here, and I'm looking at the unit again. I opened things up, and have found there to be a buildup of muck, rust and scale in the system. I dismantled and flushed the basic components the best I could, and ran a Canadian product called CLR (Calcium, Lime and Rust remover) through the burner coil. I installed 2 low point drains on my system to quickly remove water from the system to prevent freezing. Things seemed to be working well, and I used the unit for a day. Every now and then I would have a clogged nozzle tip, as something from the system worked its way out.

While I was washing, every now and then my pressure washer would stop shooting water and start shooting steam. I would remove the wand tip to clean it, and run the water until it flowed again. Eventually I started turning the burner off and pressure washed until the water ran cool. I assume there is no thermal control on the unit (none visible anyways).

Today I called around and someone suggested that there probably was "flow control issues", and to try using some form of acid to clean the system. That's all he said. So my question;

What's the best way to remove and clean the crap out of my system? Should I be running chemicals or acids through my pump, or just the burner coil and plumbing?

 

[Russ Johnson]

So as stated in my introduction post, I recently purchased a used Alkota 320x4 pressure washer. When I did the trial run, I was very disappointed. I packed it up, and stored it for the winter. Its finally starting to thaw up here, and I'm looking at the unit again. I opened things up, and have found there to be a buildup of muck, rust and scale in the system. I dismantled and flushed the basic components the best I could, and ran a Canadian product called CLR (Calcium, Lime and Rust remover) through the burner coil. I installed 2 low point drains on my system to quickly remove water from the system to prevent freezing. Things seemed to be working well, and I used the unit for a day. Every now and then I would have a clogged nozzle tip, as something from the system worked its way out.

While I was washing, every now and then my pressure washer would stop shooting water and start shooting steam. I would remove the wand tip to clean it, and run the water until it flowed again. Eventually I started turning the burner off and pressure washed until the water ran cool. I assume there is no thermal control on the unit (none visible anyways).

Today I called around and someone suggested that there probably was "flow control issues", and to try using some form of acid to clean the system. That's all he said. So my question;

What's the best way to remove and clean the crap out of my system? Should I be running chemicals or acids through my pump, or just the burner coil and plumbing?

The machine is most likely overheating because of the scale buildup. It's restricting the flow so badly that your unloader is bypassing a good bit of the water. Alkotas don't usually have thermostats...or high limit switches for that matter. One could be added on.

If you use inhibited muriatic acid, it won't necessarily hurt your pump, but there may be a scale build up in the pump sealing things up.

I use a 1/2" inlet filter with a street "L" and a 6" nipple to catch the crud coming through the lines, and enough suction hose to reach a bucket with a mushroom strainer on the end to keep junk out of the pump. Hook your discharge hose to the strainer, hang it off the side of a bucket, and put the suction line in the bucket. Add 3 gallons of water and a quart of acid, and start the machine. let it circulate for a half hour or so, dump the crappy mix, flush the coil with clean water, then do it again. It'll turn ugly brown and foam up a ton. That's the scale boiling out of it.

I do also carry a non corrosive descaling compound that is very effective.