Water doesn't get HOT enough

[Clean County PW]

When I set my thermostat at 140 degrees on my Hot water PW the water comes out about that hot. No problem there.

The problem that I'm having is that I can't get the water to come out any hotter then 140 degrees even if I set my thermostat at 200 degrees.

This is my Landa PGHW hot water PW. What could possibly be causing this problem??

I have a Temp/Pressure gauge that I put on the end of my PW hose to check it out every now and then. My Pressure always reads about right but this Temp. thing has me Confused.

If I didn't check this out the other day when I was doing some Commercial cleaning I would have never Known that my water wasn't getting that hot because at 140 degrees the steam coming off from my surface cleaner makes me think that the water was hot enough..Untill I checked it against my Gauge.

Any thoughts on this would be appreciated.

 

[Grant]

Try checking the temperature at the machine, not at the end of your hose (actually try both, you will be suprised how much temperature loss there is).
Also when was the last time you delimed the coil? This will have some affect on your temperature.

 

[ron p]

ron p

couple of things.
No matter what the mfg. tell's you about temp of water[they do tell you this] Your unit will only give a certian amount of temp rise to the incomeing water.
To get 190 deg water the incomeing water must be 65 deg. or warmer. So check the incomeing temp of your supply water. Tank water left on a rig overnight will give hotter water then spigot water[as long as it's warm overnight].
Next, when is the last time you had a maint. check by a PROFESSIONAL. Your burner tip's checked,your airband checked,your battery charged, your coil's de-scaled?
My guess is you need to de-scale your coil.
The wiz has specific directions on his site as to how to properly do this. I suggest you do this first.
Suggestion,after descaleing run some UPSTREAM soap through the pump and coil. It will give it a light protective coating so you dont get flash rust in the coil and shoot brown water on start-up's for the next 4 day's.
Good luck.

 

[Michael]

The PGHW is a generator equipped pressure washer so the battery is only used to start the engine and nothing else.

I cannot comment on the inputs used with the Beckett burner they use so I will devolve to our 4532H20.

We use a 414,000 Btu iput on this unit and the traditional rule of thumb is you need 100,000 Btu to raise 1 GPM, 140 degrees.

So with the above input you can expect to get ~108 degree heat rise at 5.2 GPM. Relative coil efficiencies will change this from manufacturer to manufacturer.

In the case of the 4532H20, typically the heat rise is 125 degrees. We draw our water from a 300' deep well so it is 50 degrees all year round. Therefore you can expect a 175 degree outlet with the thermostat fully open.

The PGHW is 4.8 GPM so you should expect closer to the 140 degree heat rise, IF they use 400,000 Btu or more for the input.

The high limit switch is set to 230 degrees. This is a safety device that turns off the unit to prevent an over temperature situation.

Manufacturers use a restrictive nozzle and/or needle valve to bypass water, reducing the flow and raising the temperature to ~225 degrees IN THE COIL. Under pressure water boils at a higher temperature. Once the water reaches atmospheric pressure the 100 C/212 F boiling point takes over and you get wet steam. Almost half the output is very hot water with the remainder steam. In this application either an additional high limit switch is used or a higer limit is set.

Coil scale will raise temperature becuase it limits water flow.

The thermostats used by every manufacturer are not exceedingly accurate.

Rule of thumb is anything over 140 degrees will prevent you from holding the metal parts of the gun with your bare hand. DO NOT TRY THIS WITHOUT PARENTAL SUPERVISION.

140 is enough to soften grease/fat/oil. 185 is enough to sanitize a surface and 200 is required to sterilize a surface.

Manufacturers do not lie per se. They will take license with the truth; like rounding up pump numbers from as low as 3.4 and calling them 4 GPM. They will publish maximum theoretical perfect condition results. They will inflate their results through printing in very small type what their inputs are to arrive at the result you see (I.E. 70 degree inlet water).

Is this wrong? Not really because the 'informed' consumer will not accept a 3.6 GPM unit when someone else is offering a 4 GPM unit for the same price. Nor will they accept a 175 degree outlet (@ 50 degree inlet) when 195 degree (@ 70 degree inlet) is available. Problem is in both examples they are exactly the same machine.

Search for the the Rules of Thumb I posted a while ago to give you the real information you require to make an informed decision. Learn the formulae so you can be sure you are getting what you are paying for.

Long answer short you are most likely getting the performance available from the machine you have. If in doubt find a local professional pressure washer dealer to do a burner tune-up including replacing/adjusting electrodes, adjusting air band and shutter, cleaning/replacing fuel filter and so on. Not only will this improve burner performance it should reduce fuel consumption and fume production.

Hope this helps? Cheers.