[Gareth H Davies]

Hi Guys,

I have a Promount 25 and it keeps cutting out/overheating when using upholstery tool.

Runs fine when using normal wand, even when just left to run whilst spraying/agitating it does not cut out.

Solution hose is hot at truckmount end but gets colder the closer it gets to the upholstery tool.

Again it runs fine when using normal wand and getting good heat.

When it cuts out the engine wont start up again until it has cooled back down.

New to the truckmount scene as i have recently upgraded from a porty.

Can anyone point me in the right direction into what may be causing this?

Cheers

Gareth

[Craigp]

It should dump hot water to regulate heat.

Does it have a temp control k-nob?

Turn temp down.

[Gareth H Davies]

yeah tried turning that down but no joy :-(

thought it must be dumping hot water as temp stays consistent when normal wand is just laying there whilst pre spraying/agitating or even when nothing is attached.

it is baffling me!!

i cleaned filter on jet in waste tank for dumping pipe a few days ago as the water temp kept rising. that stopped water temp rising. re checked it today and is fine.

[Craigp]

You need to test for sure that it is dumping, (have you actually seen it dump?)

If not, when machine is hot open waste tank lid, turn the temp k-nob all the way down, with the machine running watch inside for dumping.

[Gareth H Davies]

cheers, i was thinking the same thing but been a long day today so will check that tomorrow. luckily no stairs or upholstery to do tomorrow so shouldnt cut out, touch wood :-)

[Paul Moss]

Watch you don't start blowing heat exchangers as they are 1500 quid a go.

[Steve Chapman]

It maybe the high temperature switch on the heat box thats faulty causing it to cutout, you should be able to check by removing the appropiate fuse and seeing if its runs


steve

[Gareth H Davies]

yeah dont wanna be replacing a heat exchanger!! checked fuses and all seem fine. just dont understand why it only does it while using the upholstery tool

[Craigp]

Obviously your not using as much water with the upholstery tool, hence truckmounts need to dump to make up the short fall - it still makes the same heat.

With the wand it will rarely need to dump. Upholstery it dumps loads to stop it overheating.

[Craigp]

I highly suspect its not dumping.

ascertain that then you can look at why not, as Steve said maybe sensor.

[Gareth H Davies]

yeah does make sense, will get on case tomorrow and get back to u :-) neighbors prob wouldnt like it if i started it up now lol

[Simon Gerrard]

There should be a thermovalve, a tempreture sensitive valve connected to the pump or water box so  that if the water box overheats  the valve opens and dumps water to the recovery tank which protects the machine from overheating. When using upholstery or stair tools the flow through the water box is that much less than when using a wand and so the cooling effect of hot water in the water box being cooled by in flowing cold water and hence not triggering the thermovalve. Depending on what machine you have the ultimate protection from the system overheating is either disengaging the pump clutch or shutting machine down completely.
I'd suggest your thermovalve is stuck closed because of scale in the system, in fact I'm certain of it I given your symptoms. Descale the machine with truckmount descaler and then run up to temp (with the. A  port fully blocked off)  and put your hand of the recovery tank fitting that comes from the thermovalve, if it doesn't get hot and the machine or pump cuts out, you know what the problem is as it should get hot which means the thermovalve is working.
Simples....ish.

[Len Gribble]

Methinks its Orifice problem

[Simon Gerrard]

It could be, if it has one but the water box would be cool whereas the machine would be hot enough to shutdown, so when it shutdown put your hand in the waterbox, if it is cold then the recirculating orifice is blocked. If it's hot then it is more likely the thermovalve being faulty.

Simon

[Gareth H Davies]

cheers guys. put hand in water box and it is HOT so sounds like it could be the thermovalve. bought machine few weeks ago and it had been sat round for quite a while with previous owner. tried descaling it with acid rince but may need the proper stuff.

water box was cold when i got it, but flow from wand was hot and water temp kept rising but fixed that problem by unblocking filter on dump jet in waste tank.

[Simon Gerrard]

Well that should have solved the problem. But if not you should have a recirculating orifice somewhere that bleeds heated water back to the waterbox. If it is blocked then when the wand is closed the water in the heat exchangers builds up because it is in effect standing still and so causes a shutdown.
Sounds like the machine could do with a really good descale but when you do that make sure that you rinse the system out thoroughly not only to get rid of the crap but to rid it of any descaler which could cause a huge problem the first time you clean a carpet.

Simon

[Adrian Walton]

Sorry to hijack this thread but i have a similar problem with my Bluewave Diesel, plenty of heat but waterbox is staying cold and machine overheats if left idle for any length of time or using a hand tool on full revs.
If you look into the waterbox you can see a tiny stream of hot bubbles coming back in but not enough to get it hot to open the thermal valve, Ive descaled it but no improvment.
thanks Adrian

[Simon Gerrard]

Hi Adrian,
Same issue, blocked recirculating orofice. Because it is blocked the water is standing in the heat exchangers and then overheats. The water box should be hot, but not too hot otherwise the thermovalve will open and dump to the recovery tank. If the thermo is stuck open you will be using an awful lot of water and the fitting will always be hot, which it shouldn't be, this can also have a cooling effect on the water box temp.
Hope this helps


Simon

[Shaun_Ashmore]

The voice of experience that's why you should use forums and hopefully be nice to people who can help you well done simon.

Billy will be here soon as the word ' orifice ' gets him excited.

Shaun

[Simon Gerrard]

Billy will be here soon as the word ' orifice ' gets him excited.

Shaun

Too late, Shaun, he's already been there, that's why it's blocked up