Pressure washer idle down

[Ifixyawata]

Couldn't find anything about this on all of Google. After going through quite a few electric pressure washers I decided, with my wife's blessing to start shopping for a gas powered one.

My wife found a Briggs 825ex powered 'troy bilt' on a one day sale at Lowe's for only $199. With a $50 gift card we already had it was an easy decision.

Being the kind of person I am while waiting for it to arrive, I perused the PDF of the owners manual and found something strange. It says before you shut it down to let it idle for two minutes. Anyone know why you'd do this?

It seems like running the motor without spraying, basically making the pump bypass, I gather, is generally thought of as not good.

Anyone shed some light?

 

[LotI]

I do it with my Northern Tool unit.

Pressure washers work really hard and run hot, really hot, letting it cool off before shutoff is a no-brainer.

 

[Donald]

I have never heard of what they are suggesting.

Typically when you release the trigger on the spray wand, the pressure rises, it goes into bypass and the water recirculates getting hotter and hotter until some internal nylon valves melt.

But in idle it probably will be fine.

But a TroyBuilt is MTD junk. It's got a cheap pump good for 50 hrs max.

 

[Ifixyawata]

Looks like the actual manufacturer of troy bilt pressure washers is Briggs and Stratton. Either way it was the best spec wise unit in my price range and the ex series engine on my mower has been good.

Worlds better than an electric unit, anyway.

 

[demarpaint]

I don't ever remember idling my Honda powered power washer down for two minutes. I idle it down for about 30 seconds or so and shut it off. It has survived I'm guessing about 25 years of that, and still runs strong although the pump just started getting a little oil in the water. That's something I plan on looking into one of these days.

 

[BrianF]

I keep the trigger pressed and idle it down for several minutes. Keeps the water flowing enough to allow the engine to keep running.

 

[Linctex]

Pressure washers don't "bypass", they "Unload". Leaving them in the "unloaded state" (do NOT hold trigger) shouldn't make them create any heat at all. I think it's more for letting the engine cool down a bit.

 

[bubbatime]

If that unit has the pump mounted to the bottom of the engine, return it immediately. ALL of them are junk, and all of them have pumps that are only rated for 50 hours. You get a MUCH better unit going with a horizontal Honda GX clone engine. The cheap ones have pumps that are rated for 300 hours, so at least 6 times what the bottom mount pumps are rated at.

http://www.northerntool.com/shop/tools/product_200640597_200640597
http://www.northerntool.com/shop/tools/product_200664483_200664483
https://www.harborfreight.com/lawn-garde...-iii-62200.html

 

[dave123]

^^^^ agree for future reference and others looking to purchase Honda GX & CAT pumps what to look for pressure washers you get what you pay for.

 

[Donald]

Originally Posted By: Linctex
Pressure washers don't "bypass", they "Unload". Leaving them in the "unloaded state" (do NOT hold trigger) shouldn't make them create any heat at all. I think it's more for letting the engine cool down a bit.


Wrong, when they unload, the unloaded water goes back to the inlet. It heats up a bit more with each trip around until it gets very hot. Where did you think the unloaded water under high pressure went. Now if your commercial with a big tank of water on a truck or trailer, they dump the unloaded water back to the tank.

 

[racin4ds]

Does this unit have "idle down" feature or does it stay at 3600rpm the entire time you use it, whether or not the trigger is pulled and spraying?.

My HD unit has the CAT pump and Subaru engine, it uses what they call "idle down" technology where it only ramps up RPM when I squeeze the trigger. Other than that its idling.

 

[Ifixyawata]

Haven't received it yet but looking at the manual it looks like it doesn't have any throttle control aside from the governor.

Also says that it has a thermal relief valve where it will dump warm/hot water if it runs without spraying for too long.

 

[Linctex]

Originally Posted By: Donald
when they unload, the unloaded water goes back to the inlet. It heats up a bit more with each trip around until it gets very hot.


I have let them sit running full throttle and no flow for 1/2 hour at a time (when prepping & cleaning farm equipment for auction) and the water NEVER got "hot" at all, much less "very hot".

 

[bubbatime]

Originally Posted By: Linctex
Originally Posted By: Donald
when they unload, the unloaded water goes back to the inlet. It heats up a bit more with each trip around until it gets very hot.


I have let them sit running full throttle and no flow for 1/2 hour at a time (when prepping & cleaning farm equipment for auction) and the water NEVER got "hot" at all, much less "very hot".


Well you are absolutely damaging your equipment. That is a NO NO. You do not let a pressure washer just run for 30 minutes at a time as you go inside and make a sandwich. The time limit is 2 minutes. If you cant squeeze the wand within two minutes, then you need to shut the engine off. You are overheating your pump, big time.

 

[Rab6715]

Originally Posted By: bubbatime
Originally Posted By: Linctex
Originally Posted By: Donald
when they unload, the unloaded water goes back to the inlet. It heats up a bit more with each trip around until it gets very hot.


I have let them sit running full throttle and no flow for 1/2 hour at a time (when prepping & cleaning farm equipment for auction) and the water NEVER got "hot" at all, much less "very hot".


Well you are absolutely damaging your equipment. That is a NO NO. You do not let a pressure washer just run for 30 minutes at a time as you go inside and make a sandwich. The time limit is 2 minutes. If you cant squeeze the wand within two minutes, then you need to shut the engine off. You are overheating your pump, big time.


I agree. I have a Simpson 3100 with Honda GX and Cat Triplex Pump, its very clear in the manual to not run the engine without spraying. I do have a thermal release valve that automatically will release when pressure is to high, but my manual still stays very clear to not let unit idle without spraying. I avoid it. My pump runs pump oil that I can change, not sure about the cheap whobble/axial pumps...

 

[Woody71]

Originally Posted By: Rab6715
I agree. I have a Simpson 3100 with Honda GX and Cat Triplex Pump, its very clear in the manual to not run the engine without spraying. I do have a thermal release valve that automatically will release when pressure is to high, but my manual still stays very clear to not let unit idle without spraying. I avoid it. My pump runs pump oil that I can change, not sure about the cheap whobble/axial pumps...

I believe the Sinpson manual reads "Do not let idle for more than 2 minutes" and something about an emergency valve opening if the pump gets too hot.

 

[tig1]

Good points. Also I always use pump lubricant every time I use my pressure washer.

 

[cronk]

I have a Craftsman pressure washer that also mentions idling it for a couple minutes before shut down. Not sure if its necessary, but I have been doing it.
As far as letting the engine run without spraying, mine has a thermal valve that opens and lets the "hot" water out, its actually warm, and not very hot.
I don't let mine run long without spraying simply because I don't like wasting gas, the thermal valve saves any damage to the pump.