Delayed pump action on Symbol

I recently replaced a leaking top elbow on the red pipe on my Truma water heater.

It's no longer leaking but a new problem has developed.

When I turn on the hot tap the water comes through but there is a delay of 4 seconds before the pump starts up, likewise when I turn the tap off, the water stops but the pump carries on, also for 4 seconds.

This delayed action only applies to the hot taps, the cold water side is OK.

I mentioned this to the Truma guy at the NEC who told me to adjust the pressure switch.

Is there a pressure switch on a 04 Symbol?, if there is I can't find it.

Anyone out there got any ideas on this?

Hi Mike.

On my Exec its right next to the pump itself.

Whisky.

I wouldn't worry about it.

The cold water is limited to the volume in the pipes and therefore when the tap is switched off the pressure builds quickly and the pressure sensitive switch in the pump switches the pump off.

The hot water tank has a much larger volume of water in it so it takes the pump a few seconds to build up enough pressure to switch off. The pressure is then such that the hot tap when opened can flow a few seconds before the pump starts.

If you have the original Shurflo pump fitted then the pressure switch can be adjusted. There is a screw in the centre of the end of the pump (the black plastic end). To decrease the pressure at which it shuts off, turn the screw anticlockwise. Only a quarter of a turn at a time and then check the delay before the pump switches off. Open and close the tap a few times after each adjustment to allow pressures to settle before evaluating the time. You should eventually arrive at a position where both the hot and cold taps allow the pump to operate a similar cycle.

However as I said at the start, I would leave well alone.

Peter

Hi Mike

The water heater due to it's capacity acts a bit like a pressure accumulator so when a hot tap is opened it takes a few seconds for the the pressure to reduce to a level that activates the pressure switch and starts the pump, likewise the reverse occurs when the tap is closed the pump taking a few seconds to pressurise the heater deactivate the pressure switch and turn off.
I think you will find this is a normal operating characteristic on pressurised pumped systems.

Cheers John

Thanks for the advice guys, I'll leave well alone. More important things to sort out.