Hydramaster spitfire 4.0 questions


New Member
Feb 16, 2020
Real Name
Jane Doe
Hi all,

Ive recently bought a used Hydramaster spitfire 4.0 TM and had a few questions as this is my first machine so i dont really have any experience to lean on.

-What water temp should the machine typically run at once warmed up, and how long does it take to get there? For example, my temp gauge ranges from 100-280, and the needle wont lift off 100 until about 30 minutes of motor running. And takes a good 60 minutes to creep up to 165ish and stops there. Worth noting i live in Australia, with typical daytime temps of roughly 80 - 95°F. So its not a case of icy cold snow conditions.

-The pressure gauge was broken, so i replaced it with a same size generic PSI gauge off ebay. It still shows nothing on the gauge with the new one fitted. Winding the pressure knob all the way in/out seems to effect the water pressure coming out of the wand, so its doing something. Is there something special about the Hydramaster gauge that i need specifically that a generic replacement cant do? I cant see why else it wouldnt be reading anything at the gauge?

-It was suggested to me that i try and descale the machine due to the long warm up times mentioned above. The previous owner said to fill the mix tank with water, and loop a section of solution hose and the dump/bypass hose(that goes to the waste tank) back into the mix tank and let it cycle to clean etc. I did this, and when i was done, it just fed both hoses onto my lawn and kept feeding fresh water into the mix tank to flush it all out. But i noticed after a short while, that almost nothing was coming out of the solution hose, and a steady stream was coming from the dump/bypass hose. Im assuming the bypass hose dumps water at a certain temp, as it feeds from right behind the temp switch located behind the PSI gauge etc. But why would nothing be coming out of the solution hose at this time? I thought as long as i keep the mix tank full of water, there should be a steady stream out the solution hose regardless. I found if I disconnect and reconnect the solution like a splurt of water would come out, then it would slow to a dribble/nothing almost immediately again.

Jim Chen

Active Member
Jan 13, 2017
Real Name
How long the vacuum hose can run with the 4.0?I have a 3.2 and run up to 50 meters and still fine with the sections, can we upgrade the vacuum blower to the size of Spitfire 4.0 Roots 45 URAI-J-DSL ?