[TomCrowther]

Hi All. I am just looking for a spot of advice from anyone who runs a hotbox.
I bought a 25lpm Mazzoni in November from A1 Pressure Washers to use on certain roof cleans and to open up future opportunities. Current washer is a GX390 with a 21 lpm pump, one of Rutland Pumps. Washer works fine, reliable and plenty of grunt. I have only unboxed the hotbox, not bought any fittings or new hose which I know I will need.
My questions are around the suitability of the washer with the hotbox. Looking online, it seems I need a needle valve fitting at the very least to help regulate the flow and manage the temperature.
Is it wiser to buy a new washer, complete with needle valve/all the fittings from Rutland/Q washers etc an then have an all new, unlikely to go wrong set up or is the Honda fine and I should stick with it?
Ta. Tom

[Smudger]

Not sure what you mean by needle valve

I have 2 of those hotboxes - also from a1 - I've had them  connected to Honda  & lonchin set ups - 2 of which are Ben's from Rutland pumps

You use your unloader to regulate pressure if you don't want 200 bar - the hot box has a temp control on it

It's an in-line system so you just need a high pressure hose from p/w to the inlet of ot box - then another from the outlet of hot box to your reel - that's it

Just don't use a turbo nozzle on anything higher than 90 degrees as they don't like it

Darran

[Smudger]

I have vrt3 unloaders - I add a pressure gauge to them as well

Does your unloader look like this



Darran

[Mike Halliday]

One reason I can see for needing a needle valve is to bypass some of the pressure back to the holding tank when working at very low pressure that might not operate the flow switch on the hotbox.

So you want to work at 15bar but that low won’t push open the flow Switch so you set it at 50bar into the hotbox then use the needle valve post burner to bring it down to 15 bar.

Also bypassing the heated water back into the holding tank with a needle valve (or second downloader)  will stop heat spikes as the burner turns on and off.

[the king]

Not sure what you mean by needle valve

I have 2 of those hotboxes - also from a1 - I've had them  connected to Honda  & lonchin set ups - 2 of which are Ben's from Rutland pumps

You use your unloader to regulate pressure if you don't want 200 bar - the hot box has a temp control on it

It's an in-line system so you just need a high pressure hose from p/w to the inlet of ot box - then another from the outlet of hot box to your reel - that's it

Just don't use a turbo nozzle on anything higher than 90 degrees as they don't like it

Darran

  hi so these hot boxes go up to 150c but u can only go up to 90c as pw  dont like it ? Or am i missing something 

[Mike Halliday]

Turbo nozzles don’t like it, not all jets

[Smudger]

As Mike said just the turbo nozzle ( although I would think there are  ones rated for hotter work ) otherwise go as hot as you like because the hot box is "downstream" no hot goes through it it's the same with chemicals use something on the end of the Lance and you won't get chemical damage to your p/w or hoses

Darran