Hot water while off the trigger..Cold while on trigger...I'm triggered!

At the end of 2018 I bought a used CH1600 series Ramteq 4.8 GPM hot water skid unit with a GP pump and Vanguard 16 HP. I needed to replace a relay and rectifier in order for the hot water to work. I ordered the parts through the company and they walked me through installation and confirmed that the wiring was correct. However, when I pull the trigger, the burner shuts off, when I let off, it fires up! We checked the wiring several times and even Ramteq was baffled. Has anyone had a similar experience or any helpful guidance in this area?

I would think either they sent the wrong relay or it’s wired wrong. Is it just a common 5 pin relay? Make sure all part numbers match up with the new parts.

Is I possible that a high pressure switch has been replaced with the wrong part? Meaning it is a normally open and should be a normally closed, or vice verca? I have no experience with this, but I have a basic understanding of these setups, and that makes sense.


Ramteq Ch1600


Some pressure switches work the opposite… You may have the wrong one

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ShinedUP you are spot on.

Crabby…post a picture of your original and new relays. You may be able to just buy one from the auto parts store instead of paying a premium through the manufacturer. A lot of relays are just your basic 4 or 5 pin.

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Pressure switch is what tells the burner to fire, right? What is another name for relay, as the word isnt mentioned in the pdf.

The pressure switch is usually one of the components that tells the burner to fire. There are usually a few that have to complete the circuit in order for the burner to fire. On my Karcher the diesel tank has a fuel shortage switch that first has to complete the circuit, then flow switch, pressure switch, and then a fuel flow switch. If one of those isn’t working the burner won’t come on. They are just simple switches that complete a circuit so none of those should make it fire backwards though. Think of 4 light switches hooked together in a row and a light bulb at the end. If one of those switches is bad it won’t complete the circuit. I’m sure yours is a little different though but I would think it almost has to be a relay. As ShinedUP said they have “normally open” or “normally closed” relays. They are opposites of each other which would cause the problem that you’re having.

Do you have a wiring diagram?

The wiring diagram is in the link for the pdf i posted.

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Thanks guys. I’ll investigate this. Here is a photo of the actual pressure switch. I may need to see if it was the original or replacement.

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Also, I’ve already replaced the relay and rectifier. The previous owner had taken both of them out after the relay went bad. He just used it as a hot water unit for a while.

My bad… I missed that link above.

In the diagram #6 is the relay. You said in your first post you ordered and replaced a relay. Is #6 the relay that you replaced? Can you post a picture of the original relay and the new relay you installed?

I’m no pro on wiring diagrams so maybe someone can help verify but looking at it once you turn the burner switch on the relay stays engaged so the gun (flow of water/flow switch) has no control over the relay. So, if it were the wrong relay the burner wouldn’t be coming on at all.

See if you can find the original part number for the flow switch and make sure it has the correct one. The wrong flow or pressure switch could cause the same problem. Same idea as the relay. There are normally open and normally closed.

I misread and was thinking Shinedup and Chesebro we’re talking relay above so I think they were onto it all along.

When I was troubleshooting mine I bypassed each component one at a time in order to figure out which parts were bad. Just use a jumper wire and some alligator clips.

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I think its supposed to have the st6 flow switch stock. But that could mean nothing.

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Follow the wire from your pressure switch to the back of the thermostat. See if it’s a blue or brown wire hooked up.

I already followed the lines from the pressure switch back to the box and checked colors… I even tried to switch them to see if that would help.

Man, I was hoping that was going to be the problem. The pressure switch you have can be used as a “normally open” or “normally closed” depending on how you wire it. If the brown wire is hooked up maybe the switch is just faulty. They aren’t that expensive so probably worth trying. That’s the only switch water flow related.

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Have you messed around with it yet? I would check grounds before you do anything to involved.

I’ll check the grounds tonight… I messed with it yesterday and checked that all of the wiring matched the schematics for the unit.

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