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crd72299 · Feb 20, 2007, 06:36 PM

Hello. I just don't know what the problem is now. This is a brand new furnace. About a month. Burner was running fine, no weird noises. Than, nothing. Pump started up, but I did not hear it fire. I found it had no fuel. I tried bleeding the pump. Nothing. I had the pump bleeding, but nothing but bubbles where coming out. I disconnected the pipe and tried to suck the fuel up(I know, not recommended) I got fuel to come up the pipe aqnd held it with my tongue to find the fluid did not receed. So I am guessing there are no air leaks. So what could be the problem?

labman · Feb 20, 2007, 07:33 PM

If you have air bubbling out, it is leaking in somewhere. Since the line tested good up to where you checked it, the leak could be right where the line connects to the pump. The least little air leak on the suction side of a pump keeps it from pumping anything. Try holding your fingers around the fitting or squirting some oil on it. If you can seal it enough long enough for the pump sound to change from dry to pumping, you know you found the problem. Fixing it depends on just what type of fitting it is. Over tightening often make the problem worse.

crd72299 · Feb 20, 2007, 08:16 PM

Thanks for the help! But unfortuantly it did not seem to help. I put pipe dope onn all the fittings. Still no suction. But still pplenty of bubbles , including the ones building up in my head>:-( Still hoping to find the key to this problem.

hvac1000 · Feb 20, 2007, 08:34 PM

Originally Posted by crd72299

Thanks for the help! But unfortuantly it did not seem to help. I put pipe dope onn all the fittings. Still no suction. but still pplenty of bubbles , including the ones building up in my head>:-( Still hoping to find the key to this problem.

Check the fuel filter assembly. There has to be air in the lines from somewhere.

crd72299 · Feb 21, 2007, 09:40 AM

Ok Thanks to labman and hvac1000, I have done more and more test to come to the conclusion that air is present, I just can't find where.. I can hold pressure all the way to the pump, so I am guessing it has to be there. This is possibly the most annoying problem!! So I did another test where I had the fuel line off, sucked the fuel through a clear tube so I can see it pull up to the pump, but not go into the pump. So I think I have come to the conclusion that it is most likely the fitting I have from pipe to pump. I have put the pipe dope on both ends of this fitting, but does not pull in.

hvac1000 · Feb 21, 2007, 12:26 PM

You might have a bad shaft seal in the pump. The unit is kind of new for this but it is possible. Back in the 60's I had a vac leak that would not let me prime a oil pump. I went nuts trying to find it until I plugged both ends and put a slight pressure on the entire line. I found that the little paper gasket seal was missing on the bleed screw on the general cartridge filter. I was 16 at the time and the old oil company owner that was my mentor let me look for this almost all day while he smoked and had a few beers. When I found the problem he just smiled since he was the one that had removed the seal to start with. He said he wanted to see if I was smart enough to find the problem and if I did not find it he was going to let me go and find another helper.

I will never ever forget to replace that seal and whenever I went on a service call for a oil pump prime problem. It is the first item I check and replace with a new oil cartridge and new gaskets.

labman · Feb 21, 2007, 01:01 PM

You could try connecting the inlet, spraying that connection and the pump seal with soapy water. Then disconnect the outlet and blow into it. See if you can see any bubbles.