Replacing heating element of Isomac Zaffiro boiler?

#1: Post by **Frenchman** » January 11th, 2013, 12:40 am

I need to get my heating element (HE) out. I've disconnected all the boiler except for the temperature probe. I asked Stefano for help and he said I should be able to just pull on the copper wire for the probe and it should pull right out. It does not! I've used pliers too and all that does is dent the copper wire (so I stopped, so it wouldn't get weaker and break). Any advice?

What I really need is the HE, but I'm trying to disconnect the whole boiler so I can put it in a vice because I can't grip it strongly enough to get the HE nut to budge.

#2: Post by **tonto** » January 11th, 2013, 12:47 am

you could try a strap wrench (http://www.harborfreight.com/2-piece-ru ... 94119.html) and leave the wire alone. the larger of the two looks about right.

good luck

#3: Post by **drgary** » January 11th, 2013, 2:32 am

I wonder if the fitting around the wire can screw out? Maybe somehow it's locking the temperature probe in place.

http://users.rcn.com/erics/ · #4: Post by **erics** » January 11th, 2013, 5:54 am

Yes, the M14 nut on the boiler top holds the sensing bulb in place. That "copper wire" is a small copper tube containing an inert gas which expands/contracts with temperature.

Perhaps use a small oil filter "strap wrench".

January 11th, 2013, 10:33 am

erics wrote:Yes, the M14 nut on the boiler top holds the sensing bulb in place. That "copper wire" is a small copper tube containing an inert gas which expands/contracts with temperature.

So is it okay to remove that nut? Stefano said to pull JUST the wire (the emphasis is his) and that the probe should come out "nice and easy..." and all pictures I've seen of a Zaffiro boiler without the probe had the nut on top (that doesn't mean it wasn't just put back there so it wouldn't be lost). But that nut is quite stuck so I'm weary of loosening it unless I am 100% sure it's okay.

Are you sure that the copper tube you are talking about is no the one that goes from the boiler to the pressure gauge? That one is clearly a thin tube. The one attached to the temperature probe seems to be solid:

tonto wrote:you could try a strap wrench (http://www.harborfreight.com/2-piece-ru ... 94119.html) and leave the wire alone. the larger of the two looks about right.

Seems like worth a try. Use the strap wrench to hold the boiler and a 10" adjustable wrench for the HE nut...
Thanks for the idea. I hope the HF ones don't stink as much as reviewers say they do!

#6: Post by **stefano65** » January 11th, 2013, 10:51 am

I personally never seen it happening
BUT
if for any reason the probe Exploded and deformed itself inside the hole
could be the reason why you can not pull it out?
PS when I get very stubborn HE I use an impact wrench to remove it

http://users.rcn.com/erics/ · #7: Post by **erics** » January 11th, 2013, 11:35 am

Are you sure that the copper tube you are talking about is not the one that goes from the boiler to the pressure gauge?

Yes, I am quite sure . . . like 100%.

What prevents the probe from extraction is a "washer" of sorts at the top. And yes, that probe and the tubing contain an inert gas as I said.

#8: Post by **stefano65** » January 11th, 2013, 1:09 pm

This is the style that VBM uses on their single stage boiler
with nut washer and fitting
all zaffiro I've seen in the past had just the probe pushed in
BUT
I know that Eric will not say 100% if is not so they possibly changed the design
and although is only one nut is holding the probe in place
only one way to know
remove it

#9: Post by **stefano65** » January 11th, 2013, 1:10 pm

VBM and Isomac

#10: Post by **Randy G.** » January 11th, 2013, 1:27 pm

DO NOT put the boiler in a vise if it can be avoided at all. Put the heating element's fitting in a vice (with the fitting protected from the jaws) and loosen the fitting by turning the boiler. You could put a strap wrench on the boiler to grip it. Attach the strap around the end of the boiler, as close to the vise as possible.