[June]

Gerald,

If the Webasto Control Unit (brain box on the side of the burner) has an “A” plug (two wire plug), then the pump is the voltage of the burner.

If no A plug, you could use a VOM meter to probe the wires to the pump to see what is the supply voltage.

[Tim]

Gerald

i believe mine is a 12V but don’t quote me on that. I replaced both circulation pumps 2 winters ago. I found a school bus supply outfit in Michigan that sold the pumps. Schools in the U.P. Have webastos on their buses.

[Larry & Diane]

Chip, can I please get the School supply details?

[Chip & Pam]

Sorry for the delay, I’ve been in a nightmare scenario with our AC and RV bozo that screwed it up.

we purchased our MP straight port pumps (2 of them) from “A Parts warehouse” Lake Orion Michighan. Cost was $240 each.

https://www.apartswarehouse.com/

[Archived]

No problem Chip, thanks for the info…

[Archived]

Just be careful assuming just because one conversion has a system like yours, it also uses the same components.

There are a lot of variations between different converters.

[Archived]

Got it Jon….I do not have Webasto issues at the moment, just trying to build a conversion parts supplier database / where to inquire quickly when / if issues arise. Thanks for watching out Sir!

[Tom]

i would say that if the control box says 24 volts on the side of it, the motor would be the same.

I have a noisey pump also, but when I take it out and run it, it is so quiet I didn’t think it was working.

[Bill]

It may need to be run under the same load conditions as it is when installed.

Also when the water heats up and exspands the internal parts it may be having a problem then.

[Tim]

My pumps will come on when heat is called for in the coach or the hot water tanks call for heat or I have the Central Heat controll turned of which is just heat for the plumbing bays. (if your heaters have the Webasto or engine heat loop)

When the engine coolant is above 140 degrees the burner will not come on but the pumps will circulate coolant to the device calling for heat.

Your pumps should only run when something is calling for heat.

Hope some of this makes sense.

In short, the pumps should only run when the burner is firing or the engine coolant is hot enough th not need the burner.

[Jerry]

On libertys the circulation pump stays on all the time if the Webasto button is on even if the heat exchangers and fans are not on so there is hot coolant at the ready when the thermostat calls for heat when parked the motor heats the coolant when driving

[AL]

As you can see, depending on Converter, the pump may or not run continuously. I’ve had both.

[Archived]

Ditto, what Tom (Admin) said.

[Greg]

Thanks

I will try and set up a relay from the dash to trigger the webasto.

[Tim]

Pres,

I am not familiar with your circulating pump, either its configuration or performance specs so take my comments with that in mind.

I have a substantial Webasto circulating pump that could have been installed by Liberty or Prevost. I don’t know who it was but I do know if the motor fails I will shop for a motor that will mate to the pump. There are standards for things like motor size and attach points so I will just match the motor to the one on there. It will likely be on the shelf at WW Grainger.

If the pump has failed I will do an internet search for circulating pumps and find one as close to the one I now have. Circulating pumps are not pressure pumps and their purpose is just to keep a liquid flowing. They are common for a lot of applications so finding one should not be a challenge.

It might not mate up to your fittings exactly, however plumbing is simple and you are very likely to have little or no cost associated with installing a pump with slightly different dimensions because in my coach the connections are via hose fittings meaning a piece of rubber radiator hose can be cut to the correct length and I am back in business.