Solar iboost and external Willis heater problem

tonybodhran

Hi guys, looking for some advice.

I had a solar installation with solar iboost system recently. The solar iboost blew the immersion element and the installer decided to put in a Willis external heater in because the heater element was stuck and he was afraid of deforming the tank trying to get it out to replace it.

When the Willis was installed we didn't realize until afterwards that the hot water was not getting to the tank. It seems to be stuck going from the Willis to the T junction it joins into past the immersion outlet.

My thinking of that this is because it was installed past the actual outlet and should have been installed before the outlet does that sound right?

I've attached photos hopefully that helps.

Any advice appreciated thanks.

John.G

The heater outlet must rise continuously to join the cylinder outlet, if the pipe cannot be bent then maybe use 45 deg elbows to achieve this, also 3/4" piping.

Read thread 'Fitting a Willis Immersion Heater", below.

The Continental Op

I've been looking a Willis heaters for a while and a first glance at the pictures would lead me to expect that set up to work. I don't think its optimal but it should heat the water in the tank.

If there is a problem then its down to the dead level section at the top. The Willis is heating the water in its little tank but cutting out before the thermal siphon kicks in. So as above a bit of a rise in the pipe from the top of the Willis to the tank would get it working. I'd also put the T on the top of the tank and so reduce the length of pipe run for the Willis.

Edit> looking again at the photos it looks like that top horizontal pipe actually dips down a fraction towards the cylinder, just cutting 2 inches out of the pipe above the Willis and connecting it back up might just get it going - but not idea.

tonybodhran

So you both are basically saying that the Willis outlet needs to rise towards the tank outlet I think yes? I was going to suggest that the installer put a new T out of the top of the immersion outlet and go in directly before the immersion outlet, would this and the rise from the Willis to the outlet solve the problem completely?

Thanks for your time.

John.G

There are no guarantees with these installations.

The vent/HW outlet (assuming a vented cylinder?) on yours turns directly left as soon as it leaves the cylinder top and the willis flow should be higher up, above the HW take off like in the attachment, not sure how you can achieve this, 3/4" piping also a must IMO (which you may have) and if any isol valves installed must be either gate valve(s) or full bore Lever (ball) valves.

The horizontal piping, even though shown as being "horizontal" must as far as possible also be rising.

Willis Heater Installation 1.jpg

tonybodhran

Ok thanks for the help everyone.

The Continental Op

Don't forget to let us know how you get on and what was done to make it work.