Hooked up my new chiller...and nothing....Plumbing question

[dowsetts101]

Given we’re coming into summer here in Melbourne getting my chiller sorted is top priority at the moment. Over the past few weekends I’ve been finishing off the outdoor enclosure for the chiller (and the rest of my mixing station). Yesterday I put the roof on, so today was spent finalising the plumbing and connecting it all up.

I did my best to prime the intake pipe for the pump, and then turned it all on. I could hear the pump working, with some water (and lots of air) but very very little flow.

Back in the sump, I could see some water being pumped, but it was more “surging” with the water level slightlly raising (5mm/ 1/4”) but practically nothing.

I think I potentially have two issues. I effectively have an air trap at the inlet, where the water needs to be pumped vertically for around 300mm/12” before gravity takes hold. Then I’ve got a 10m run of pipe, with fall of around 1.6m/5’ 3” before reaching the pump.

The pump is a Fluval SP4, which should have plenty of flow at this head (5650 L/hr 1492 GPH), but not sure if it can cope with the amount of suction that I’ve forced it to cope with.

As I see it, if that all is the problem, I’ve probably got 2 options. Change over to a pump more suited to that configuration, or put the pump in the sump (or at least in the sump cabinet so it needs to deal with less suction).

What do you think? Are those my issues? Anything else that I’ve missed? My sump is pretty crowded with plumbing to getting the pump into the sump is going to be a struggle I think.

Appreciate any thoughts/suggestions you may have.

Water change station (now has cladding and roof)

Chiller and pump are in the right hand chamber under the RODI unit

Schematic of the plumbing

Plumbing in sump...intake for chiller is highlighted

 

[ca1ore]

Almost certainly air in the suction piping is the problem. Even if you prime the pump chamber, a second after turning it on that water is gone, replaced by air from the input pipe. You’re going to have to find a way to remove air from that pipe at which point the pump will work fine. I had a chiller pump set up like this and it was such a pain that I reconfigured it.

If possible, I always recommend putting a chiller on the main return. Upsizing plumbing helps to mitigate friction losses.

 

[dowsetts101]

Almost certainly air in the suction piping is the problem. Even if you prime the pump chamber, a second after turning it on that water is gone, replaced by air from the input pipe. You’re going to have to find a way to remove air from that pipe at which point the pump will work fine. I had a chiller pump set up like this and it was such a pain that I reconfigured it.

If possible, I always recommend putting a chiller on the main return. Upsizing plumbing helps to mitigate friction losses.

dang...I was sort of hoping that there might be some magic fix...but suspected that wouldn’t be the case!!!

Anyway, I’ve had a bit of a play around and have moved the pump up into the return chamber in the pump and close the circuit with the chiller.

This is probably the path of least resistance as a first attempt. I’ll wait for the PVC cement to dry and then will hopefully test it out later tonight.