Honeywell 40004850-001 isn't working. The lever to manually open valve freely moves back and forth. What do I need to do to replace this valve?

Are you trying to replace the power head of the whole valve?

http://customer.honeywell.com/Techli...0s/60-2133.pdf

Do you have shut off valves on both sides of zone vavle? IF you do, shut them off, and remove the four screws at each corner of zone valve(dont do this if you don't have isolation valves at each side of zone valve). Then pull the head off the vavle. Now, there will be a rod sticking out of valve cover plate that has to flat sides. See if you can move this rod with your fingers. If you can, you just need to get a new head(the part you just took off). If you cant, you will need to cut out complete valve assembly and solder in a new one.

If you don't have any isolation valves, you will need to shut of incoming water to boiler, drain complete system, then replace either the head of complete unit(unless you have a newer style zone valve that only the head needs to be replaced on) Once your done replacing head or complete valve, turn water back on to boiler, then go and bleed all of the air out at bleeders on registers. If you have to break into the system, and there are no isolation valves, this can be a very time consuming project to take on. You May want to think about having a pro in to do the work. Good luck and please let me know how you make out. Lee

If you have the older style valve then you can use this kit with the old valve body to convert to newer style unit. This way you do not have to remove (unsolder) the old valve body. Save time and a headache.

Conversion Kits:
Conversion kits for converting old style (series 1-5) valve
bodies to accept 40003916 Powerhead (use with V4043,
V4044, V8043, V8044). Includes metal plate with driveshaft
and rubber ball, O-Ring and four screws.
Two-way water valve body: 40003918-006.
Three-way water valve body: 40003918-007.

Two-way steam valve body: 40003918-008.

I just need to replace the diaphragm. It was replaced last Dec. 2011, It is not working again this year. It may be stuck. I would like to open it and see if I can free it with WD-40 or replace it if it is damaged already.

Mick
[email protected]

It is a swing ball style?

See below

https://customer.honeywell.com/resou...0s/60-2133.pdf