Major problem with march pump.

SSBrew - 728
Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
AshtrayDinner

AshtrayDinner

Well-Known Member
Joined
Feb 25, 2009
Messages
53
Reaction score
2
So I'm brewing with my new equipment for the first time today. This meant grinding with my new drill powered grain mill, Mashing in my new mash tun, boiling in my kettle, and then running the wort in through my new march pump and counterflow chiller.

However when I reached the chilling part of the process the pump failed to move the wort through the coil at all. I had noticed that the flow from the pump was fairly minuscule while pumping my cleaning chemicals through the coil during prep. It was enough though, that I figured everything would go fine.

Not so! When I turned the pump on to pump the hot wort through the coil, into the carboy, it failed to create any flow at all. I've sanitized the outside of the counterflow and am using it like an immersion cooler in an attempt to salvage my batch of beer.

I am hoping that someone knows what I'm doing wrong, and can point me in the right direction.

Thanks.
 
The march pump is not self-priming, which means you need to get all the air out of the pump and the "input" line. The easiest way to do this is to put the pump below your input vessel, and your output line below your pump. You don't even have to turn the pump on, just open the valves. This will start a siphon, and when the air bubbles have cleared the system you can shut off the valves. I usually do this at the beginning of the brew day, and never have to fool with it after that.
 
What size and type of fittings and hose are you using on the pump? How long are the hoses? Do you have some sort of screen in your boil kettle, or are you using hop bags?

Try having the inlet of the pump hooked up to a keg full of cold water, and just lay the outlet hose end on the ground. let gravity push water through the pump and push most of the air out. Now plug the pump in. Does the water come rocketing out?
 
Did you make sure the all the air is bleed out of the lines going into the pump and the lines coming out of the pump have liquid in them. These pumps will not prime themselves and if there is any air in the lines the pump will cavitate not allowing liquid to flow.
 
I definitely tried to prime the pump, as I was instructed to do.

The line flowing out of my kettle and into the pump is about a foot and a half. I made sure to open the valve on the kettle, and let the line and pump fill with wort before turning on the pump, and to have the pump lower than the kettle so gravity would continue to feed the wort through the pump.

The line flowing out of the pump is maybe three or four feet long, and flows down at first, and then up into the counterflow coil.

I was just throwing the pelleted hops straight into the boil. I have hop bags, but have felt in the past like they muddle the flavor of the hops, by not allowing them to dissolve enough.

I believe I am using 1/2" braided pvc tubing, and 1/2" fittings for the pump. The outlet line from the pump flows into a hose reducer and then into smaller hosing so it can attach to the small end of the cooling unit.

Thanks for your prompt responses, I believe I saved my batch by using my counterflow cooler like an immersion cooler, but I am mortified that I can't get my $200 pump to work.
 
AshtrayDinner said:
I definitely tried to prime the pump, as I was instructed to do.

The line flowing out of my kettle and into the pump is about a foot and a half. I made sure to open the valve on the kettle, and let the line and pump fill with wort before turning on the pump, and to have the pump lower than the kettle so gravity would continue to feed the wort through the pump.

The line flowing out of the pump is maybe three or four feet long, and flows down at first, and then up into the counterflow coil.

I was just throwing the pelleted hops straight into the boil. I have hop bags, but have felt in the past like they muddle the flavor of the hops, by not allowing them to dissolve enough.

I believe I am using 1/2" braided pvc tubing, and 1/2" fittings for the pump. The outlet line from the pump flows into a hose reducer and then into smaller hosing so it can attach to the small end of the cooling unit.

Thanks for your prompt responses, I believe I saved my batch by using my counterflow cooler like an immersion cooler, but I am mortified that I can't get my $200 pump to work.
Click to expand...

I am guessing that the pump is not the problem. I think (and this is a guess without seeing you setup) is that the hop debris is causing a clog somewhere. This is easy to verify. Now that your batch is done, make sure everything is clean and try your setup with water only. I am guessing that it will be fine. Go to home depot and get a paint strainer for next time and throw your hops it there and put it in your boil kettle. They will dissolve just fine.
 
I ran into the exact same issue this weekend. I ran several dry runs with my system before brew day with no issues.

The pump ran with no issues for the whole session. Once I started the whirlpool chiller it work fine, then came to a screaching halt.

The pickup tube was completely clogged. The stupid thing was that I used hops bags, except for my first wort hopping, didn't even think of it.

During cleaning it worked flawlessly, so next batch I will be using hops bags on all my additions!
 
caspio said:
Do you have some sort of screen in your boil kettle?
Click to expand...

Pellet hops are notoriously bad for clogging things up. I have a relatively small screen on my kettle outlet. It works great with whole hops, they form a nice filter bed. With pellet hops though, it literally only takes an ounce or two to form a layer of gunk on the screen that completely blocks all flow.

Another thing to think about - sometimes if I do a longer boil and/or use whirlflock, I get a massive hot break. Sometimes this gets coated onto the screen, and I have to use the brew spoon to scrape against it and clear things off.

Like myself and other folks have said, do a test run with just water
 
cashbrewing said:
if there is any air in the lines the pump will cavitate not allowing liquid to flow.
Click to expand...

Not to nitpick or threadjack, but I keep seeing the term cavitation being misused in the forums....

Cavitation occurs when your impeller/propeller pull so much vacuum that it drops the pressure below the vapor pressure of the liquid. This causes bubbles and with them energy spikes that cause damage to impellers/etc.

I strongly doubt a mag drive march pump can pull enough vacuum to cause cavitation...

:tank:
 
leboeuf said:
Not to nitpick or threadjack, but I keep seeing the term cavitation being misused in the forums....

Cavitation occurs when your impeller/propeller pull so much vacuum that it drops the pressure below the vapor pressure of the liquid. This causes bubbles and with them energy spikes that cause damage to impellers/etc.

I strongly doubt a mag drive march pump can pull enough vacuum to cause cavitation...

:tank:
Click to expand...

It is also when bubbles are formed on the suction side by the impeller which causes a loss of pressure and efficiency on the pressure side of the pump. This is issue is multiplied when applied to a hot liquid. Damage only occurs in high output/large volume pumps.

Literally cavitation means ": the process of cavitating: as a: the formation of partial vacuums in a liquid by a swiftly moving solid body (as a propeller) or by high-intensity sound waves ; also : the pitting and wearing away of solid surfaces (as of metal or concrete) as a result of the collapse of these vacuums in surrounding liquid b: the formation of cavities in an organ or tissue especially in disease"

On the engineering side you are absolutely correct.

However what is described here is more like air ingestion, given that it is occurring due to already present air being churned by the pump while it is trying to prime. Cavitation can occur with the March pumps when you start pushing boiling wort through after having a cooler liquid in the lines.
 
I had a similar problem when I had originally placed the chiller high on my rig, higher than the receiving fermentor. I solved it by changing the position of the CFC so that its outflow is now below the top of the fermentor; still higher then the pump. This makes the pump push the cooling wort through the length of the chiller and out a short section of hose into the fermentor.
 
leboeuf said:
I strongly doubt a mag drive march pump can pull enough vacuum to cause cavitation...

:tank:
Click to expand...

A small magnetic drive pump certainly is capable of cavitation. I haven't measured the max suction psi, but it's substantial when the pump is properly primed. I have measured the vacuum in excess of 5 psi, but the output valve was barely open. I have a vacuum gage on my RIMS to monitor the suction. Now 5 psi may not seem like much, but atmospheric is only 14.7 psi at sea level, etc. It's enough to cause cavitation under certain conditions and the most common for us home brewers is when moving hot liquids. I can easily pump 200 F wort, but anything hotter will result in cavitation and the subsequent loss of prime. I'll check the max suction next time I fire it up.
 
I think by saying cavitation we mean air got into the pump head causing it to lose its prime you're probably right that it is the wrong term but it sounds more cool to say.
 

Similar threads

bf514921
Pump Mounting hardware or brackets
Replies
16
Views
653
bf514921
bf514921
maddjaxx
Sold March 815 SS pumps
Replies
1
Views
529
maddjaxx
maddjaxx
E
Sold SOLD - 20 Gallon E-HERMS brewing system. SC
Replies
4
Views
536
LakeHartwellSkier
LakeHartwellSkier
V
Whirlpooling and chilling
Replies
15
Views
1K
JohnDBrewer
J
D
Interesting pump flow discovery/idea
2
Replies
51
Views
4K
day_trippr
day_trippr
Brewer's Friend 300

Latest posts

Back
Top