Pigtail

BreakasDIY

Hi,
I notice that my boiler is still firing at 4 psi even though the pressuretrol is set with a cut in at 0.5 psi and differential at 1, meaning that it should have kicked off at 1.5 psi. I therefore want to change/clean the pigtail but the plumber didn't leave a big enough gap to screw off the pressuretrol which needs to come off to get out the pigtail.
My question is, can I cut the pigtail in half and remove the pressuretrol this way and when reinstalling add a 3 inch nipple with a union to the top of pigtail (effectively raising the height where the pressuretrol will now go into), will this effect the pressuretrol sensitivity or effectiveness since it is now further away from the low water cutoff where the pigtail is screwed into?

JohnNY

Can you spin the whole nipple/elbow out of the boiler? If not, then yes, cut something and reassemble as necessary later.

BreakasDIY

JohnNY said:

Can you spin the whole nipple/elbow out of the boiler? If not, then yes, cut something and reassemble as necessary later.

Will the extra 3-4 inches that the pressuretrol will be sitting higher from it's original position affect its function at all (since it is further away from where it was meant to be originally)?

Hap_Hazzard

BreakasDIY said:

Will the extra 3-4 inches that the pressuretrol will be sitting higher from it's original position affect its function at all (since it is further away from where it was meant to be originally)?

Aside from not needing to bend over as far to read or adjust it, it will have no other effect. As long as the wires will reach, you're in good shape.

Don't forget to add some water to the new pigtail before you mount the pressuretrol. Are you replacing it with a brass one?

BreakasDIY

Yes I am replacing with a brass one (current one is also brass). Thank you everyone for your help, it is very kind of you all to share your professional experience with novices such as myself.

Hap_Hazzard

You'll do all right. At least you've got the brains to put a union under the pressuretrol. I'm embarrassed to say how many time I disconnected and reconnected those wires before I got that idea.

Fred

You may find that the pigtail is clear. Pressuretrols are notoriously out of calibration, right out of the box. Once you check the pigtail, if you actually need to recalibrate the Pressuretrol (if it is the Honeywell model 404) here is the calibration procedure:
Pressuretrol Calibration
Inside the Pressuretrol, right below the micro switch, there is a pivot arm. At the end of that arm you will see a screw pin that is activated by the diaphragm at the bottom of the Pressuretrol. If you look very carefully at that screw pin, you will see it actually has a tiny (I mean tiny) hex head on it. It takes a .050 hex wrench and you can turn it clockwise (Towards the bottom of the Pressuretrol to decrease the Cut-out pressure or counter clockwise to increase the cut-out pressure (which none of us want to do but who knows, your Pressuretrol may be really screwed up!). Turn the power to the unit off first. You may find the first attempt to turn that screw a little bit stubborn (relatively speaking) because it has some Locktite on it but it does turn. Don't turn too much, a fraction of a turn goes a long way towards getting it adjusted where you want it (maybe 1/32 inch turn to start with). You may need to play with it to get it exactly where you want cut out to be.
NOTE: The little hex screw will have a dab of locktite on it. You may have to heat that locktite with a small soldering iron to melt the Locktite and turn the screw.

Chris_L

You probably don't need to cut anything to remove the Pressuretrol.

If you are at all mechanical, you can separate the diaphragm from the body with the four screws on the bottom--assuming this will give you enough clearance. First, reduce the tension on the adjustment springs as much as possible. And don't lose the pellet that sits on top of the diaphragm. You should then have room to unscrew the diaphragm from the pigtail.

Make sure the pigtail is clear and the Pressuretrol is seeing the boiler pressure (the fittings could also be plugged). When reassembling the Pressuretrol, leave the adjustments completely loose (otherwise it is very hard to get the four screws in), and be sure the pellet that sits on the diaphragm is centered properly. Then, put it all back together with the union and extension as you describe.

Some pros (and others) will frown on this approach. But if you are careful, it is easy to do. I've done it a number of times.

Long Beach Ed

We pipe the pigtail manifold with a try-cock. You can open it to check if the pigtail's clogged.