Motorhome Water Pump Problem

Sounds like maybe your frost control valve has opened?

Chech this out as a start :

https://www.truma.com/uk/en/water-systems/accessories-water-system.php

I wonder if the emptying valve for the water system is still in the open position? Somewhere between the pump and the water heater is a three way lever, In the upright position it will drain the water. The only alternative I can think of is that a waper pipe has come loose. The pump will always come on for a few seconds just to prime the system but it should go off after a very short time.

David

it may be the boiler dump valve left in the open position from the last time it was drained, or even an automatic frost protection valve which might need closing.

had both these on our van, usually first time out after draining down....brain fade i guess....

edit: snap you two.....even with faded brain, great minds etc....

you can tell which one it is by getting under the van and tracing the discharging pipe back up into the van to locate the source.

Same thing happend on our swift motorhome it turned out to be the vent pipe on the truma water heater 

when you empty the water heater ( for over wintering  ) via the valve that's normally on the floor or in a cupboard somewhere there is a one way valve that lets air in the heater to allow it to drain the water out otherwise there would be a vacuum and the water would drain very slowly ( Basicly a plastic ball on a seat in a one way valve  ) 

on our van the ball disintegrated so as soon as the water pump switched on the water pumped out the vent pipe that came out under the van (Truma do the spares for this very problem)

Hope this makes sense 

Chris