Webasto Thermotop

[Nobag]

Just wondering what peoples definition of the boiler cycling is.

1: Going to half speed when the correct water temperature is reached.

2: The boiler shuts down when correct water temperature is reached and then restarts.

 

[Ex Brummie]

Not too familiar with Webasto's, but I doubt if anything designed for a boat or truck would have a modulating burner, so I would think option 2.

[NMEA]

All Webasto, Eber and Mikuni boilers are modulating, cycling is when the coolant quantity is so small and the radiator load so small that the unit is not allowed to works as it should which is to heat the water to temperature and then maintain it using half power. If the heat produced on half power is not dissipated by the load the coolant temperature continues to rise and the unit shuts down its burner and continues to circulate the coolant until such time the returning coolant temperature drops to a level where the burner fires up again, and so the cycle begins again. The latest Webasto evaporator boiler due to be released soon (already available in 24VDC) has more steps in the heat output so should go a long way to reducing cyclings in poorly designed systems.

Edit to add tat the above applies only to evaporator heaters and not pressure jet boilers.

 

Edited December 11, 2017 by NMEA
Extra info

[Nobag]

Thanks for the replies

So the boiler going from full to half heat when the correct temperature is reached, and then back up to full heat when the temperature drops is normal behaviour.

Cheers

[NMEA]

Its acceptable, but if installed to Webasto protocol with correct loading it should rarely happen, especially if the unit is only run for a couple of hours as recommended.

[Ex Brummie]

1 hour ago, NMEA said:

All Webasto, Eber and Mikuni boilers are modulating,

Edit to add tat the above applies only to evaporator heaters and not pressure jet boilers.

 

Every days a school day. I'll stick to my vaporisers and pressure jets.