Toyo pump - makes a lot of noise when operating

hoofinitnorth · #1 02/13/07, 07:22 PM

I have a Toyo brand fuel lifter pump. It was installed professionally a few years back (they didn't do a good job, we had to replumb it as they reversed the inlet & outlet!!!). It appears to be within the manufacturer's specifications for max. lift and distance from the tank. It works. It just makes a lot of noise when the pump is activated and it's in our bedroom. We don't hardly notice it anymore but I did flip through the manual and it may be missing a check valve (these apparently don't come with it but the manufacturer says to install one??). Maybe not. It doesn't appear to have any way to leak and it doesn't appear to have an airlock.

Any ideas or experiences with these? I plan to go to the plumbing supply store in a couple of days to ask about this and the check valve...

agmantoo · #2 02/13/07, 07:47 PM

A pump that cavitates will make a lot of noise. If the inlet and outlet were reversed then maybe the supply and discharge piping was installed reverse also. The supply line in most pumping situations will be larger than the discharge.

agmantoo · #3 02/13/07, 08:11 PM

I failed to ask about an inline filter in the supply line. A too small filter or a fouled filter element will create a problem on the supply side. Does the noise change with major outdoor temperature difference?

hoofinitnorth · #4 02/13/07, 10:39 PM

I'm not following your first post. Sorry, I'm slow.

There is an inline filter at the tank and it is in good shape, recently replaced. The pump has always made this noise and it doesn't matter if the temp. outside is -30F or 80F. Also doesn't seem to matter if the inside temp. fluctuates up or down a max of 30F (between winter and summer).

agmantoo · #5 02/13/07, 11:26 PM

I was asking questions which you answered in an attempt to isolate the problem. All we have done is IMO to eliminate some of the possible causes related to temperature/viscosity. Are the input and output lines to the pump the same diameter? Are there a lot of elbows or other restrictions on the input side of the pump? How far away is the storage tank from the pump? Read here for what I think is happening with you pump and some possible remedies.

http://www.micropump.com/tech_tips/cavitation.asp

hoofinitnorth · #6 02/15/07, 02:38 PM

Almost a straight shot up from the tank to the bedroom - I think there are two elbows/tees. The input & output are same diameter (1/2" copper I think). The pump is on the second floor of the house directly above the tank, which is set just above grade. I think the total lift is no more than 16'.

Will check out that link.

agmantoo · #7 02/15/07, 04:21 PM

Is there a return line to the tank? Can the pump be mounted closer and lower to the tank?

hoofinitnorth · #8 02/15/07, 04:29 PM

I don't believe there is a return line to the tank but there is a continued outfeed to the other Toyostove in the lower level. The pump raises the fuel to the second level, feeds the first stove there, then gravity feeds the second stove down below (of course the pump has to come on to make sure there is enough upstairs to gravity feed to the second stove).

There is no way to lower the pump, unfortunately, but it is well within Toyo's guidelines for max lift & distance.

We have been thinking about changing the filter type on the tank. Might be the first step.

I read that site you gave me and it helped me understand the process of cavitation, some what. Would the addition of a check valve help this problem?

agmantoo · #9 02/15/07, 04:35 PM

I am unaware of any benefit from a checkvalve regarding noise.

agmantoo · #10 02/15/07, 04:42 PM

Each stove must have some method of turning the pump on in order for the gravity stove to run when the second level stove is off. Do you know how this is accomplished? Can you give me the name and model of the pump so I can research the design, I want to know if it is a gear pump,vane or a diaphragm design.

hoofinitnorth · #11 02/15/07, 05:12 PM

The pump has to be on but the upstairs stove does not have to operate in order for the downstairs one to work. In fact, the upstairs one rarely runs because of our layout (we're working on supplemental heating using other methods to betterput the heat where we want it but the upstairs heater was a safeguard to make sure 2nd level plumbing doesn't ever freeze). When downstairs one needs fuel it opens it's lines to receive fuel, supposedly creating a negative pressure and drawing fuel in from the gravity-fed lines and then the pump senses the negative pressure on its end and turns on. I think. I may be wrong or oversimplifying it though.

Using the Laser AT60 as shown here: http://toyostove.com

I just found this site - I will email them too about the pump problem.

agmantoo · #12 02/15/07, 06:25 PM

Is figure 10 on page 13 like your setup
http://www.toyotomiusa.com/products/...s/OPT-81UL.pdf

hoofinitnorth · #13 02/15/07, 07:28 PM

Yes, I believe that is like our setup.

agmantoo · #14 02/15/07, 07:38 PM

Is there a cutoff valve to the first floor heater near the heater? If so, cut the fuel to the first floor heater and run the second floor heater until the pump comes on. See if the noise is the same. If this corrects the noise problem then you need the checkvalve at the first floor heater. If I am unclear on this ask for a restatement from me.

hoofinitnorth · #15 02/16/07, 12:31 PM

Yes, there is a cutoff valve and yes we have done this before while making repairs. There was no change in the sound of the pump.

Really appreciate your help here, agmantoo.

agmantoo · #16 02/16/07, 04:17 PM

I have reviewed a number of the drawings for your type pump but the info on the pump itself is minimal. How high above the floor (second level unit) is the lift pump located? Do you see any possible place, on the supply line from the storage tank to the second floor pump, where air could weep into the supply line? Are the valves opened to a snug position? Is there any "weeping" anywhere around the valves? I am about convinced that air is getting into the sytem from somewhere, either sucked from the lower level gravity fed tank or a joint in the plumbing supplying the 2nd floor unit or a possible drainback from the 2nd floor small fuel storage tank and its fuel feed into burner lines. There are to be small rubber mounts on the pump housing to wall attachment.

hoofinitnorth · #17 02/17/07, 10:32 PM

The pump is mounted about 5' above the floor on the 2nd story. There are no leaks or areas where we see air getting into the system. We've also not observed any sounds of suction or air movement anywhere along the piping (currently all exposed) when the pump is running. The only place we can think of where air is getting into the system would be at the pump itself. It has a small rubber gasketed top inside the pump that goes over where you see the wheels turning in with the fuel.

The rubber mounts are in place on the back of the pump between the pump and the wall.

When it's daylight again, I'll have my husband take a look at the gravity-fed lines to see if he can see anything there.

Thanks again!

agmantoo · #18 02/18/07, 11:17 AM

Look this over in an attempt to see something I have overlooked
http://www.rural-energy.com/publicat...cument-290.pdf

hoofinitnorth · #19 02/21/07, 11:50 AM

Doesn't look like you've overlooked anything. We can't find any place where air might be getting into the system except at the tank itself (but we have not allowed it to get low to suck air into the outflow) or the pump. I wonder if the heaters themselves could be sending air back into the system?

I emailed the manufacturer and they are trying to help a bit but so far they are having difficulties troubleshooting via email. No wonder.

Anyway, will post if we find out anything.

Thanks again.