Honeywell Zone Valve Replacement

I have a problem with one of the zone valves for my hot water heating. The heating company identified it as a zone valve. The power head is bad. It looks pretty old but I found a matching replacement. Honeywell V8043F 1051. Should I beable to swap the powerheads out? Will I need to drain the system? I prefer to purchase the whole valve so that if the power head doesn't fix it, I still have the option to replace the whole valve.

I replaced 2 zone valve by changing the powerheads only. No need to drain the pipes. I got the same model#, removed few screws holding the power head, in goes the new one, simple job.

Thanks Alex,
Were they Honeywell V8043F zone valves? The reason I ask is that the heating company technician, who admitted that he had never replaced one before, started removing screws and water started coming out. He then determined that the project was a bit bigger than he antisipated and raised the price. I decided that if it was his first time, that I could do just as well. If I was going to stand there and watch him figure it out, I might as well figure it out myself. I do have some mechanical skills and plumbing experience.

Anyway, I'm going to give it a try. If I get myself into a jackpot, I can call my master plumber cousin to bail me out....

Just looking for all of the preliminary advice I can get before I start taking the thing apart.

My old system had Honeywell V8043F and I changed one powerhead. No water leaked while changing the powerhead.

It should be fairly easy to tell if the powerhead failed or if there is another problem. What are the symptoms?

Honeywell V8043 E 1012 motorized valve. One of the features listed on the box is " Removable powerhead". I hope this helps. Alex44.

Thanks CHH and Alex,
I have two zones. When I adjust the temp setting on Thermostat A, that zone functions. When I adjust Thermostat B, there is no response. Thermostat B does seem to open the zone valve for Zone B, but the circulator pump doesn't react unless zone A is also activated at the same time. I can tell this because, if I set the temp on zone A & B to 90 degrees, water circulates through both zones. If B is turned off and A is set on 90, only A circulates.
If B is on but A is off, nothing happens.

I hope this makes sense. It's hard to describe.

I had this same problem. It turned out to be the switch in the powerhead. It is all one piece. The powerhead rotates and hits a switch. This switch tells the pump to kick in. A simple powerhead swap did the trick. This is a common fault to the powerhead from what I hear.

Just to follow up, I replaced the power head on the zone valve this weekend. I did have to drain the system. The new version of the valve has corrected the problem, but the old version would not allow you to remove the power head without breaking the seal.

The valves have the same serial number, but honeywell has made improvements over the last 40 or 50 years. The next time I have to replace the powerhead, it will be easier. Unfortunatly, it's more likely that the other, old valve will go bad first.