boiler knock ???

Mitch_6

If you do not also reverse your zone valves you may find they chatter or bang shut.

phastcall

Boiler knock ????

I have a customer with a weil mclain boiler newly installed by a contractor who has stopped answering his phone. This hot h2o boiler is piped with return water to top of boiler with expansion tank upstream of circulator on what should be the return connection of boiler. Zoned with taco "grenade"valves, this system heats to near setpoint, begins knocking and shoots small droplets from relief valve but pressure is around 15lbs. it sounds the same as a "snapping" steam pipe and stops the second boiler satisfies. I want to flip the circulator up side down, but the taco valves are directional and i dont think they will work right..... what do you think ?

phastcall

Boiler knock ????

I have a customer with a weil mclain boiler newly installed by a contractor who has stopped answering his phone. This hot h2o boiler is piped with return water to top of boiler with expansion tank upstream of circulator on what should be the return connection of boiler. Zoned with taco "grenade"valves, this system heats to near setpoint, begins knocking and shoots small droplets from relief valve but pressure is around 15lbs. it sounds the same as a "snapping" steam pipe and stops the second boiler satisfies. I want to flip the circulator up side down, but the taco valves are directional and i dont think they will work right..... what do you think ?

Weezbo

Sounds like a Miracle .to me *~/:)

Ken_34

Boiler Knock

You've got return water driving the aquastat. Reverse the flow and you'll get the true water temp reading at the aquastat.

Anthony Menafro

Return

Why is the return water piped to the top of the boiler? It should be piped to the side of the unit at the bottom. You can't flip the circ. because of the zone valves? Flip them and put the circ. on the top PUMPING AWAY from the boiler and alter your piping to adjust it. After this is complete, you'll have no more knocking or spitting.

Anthony Menafro

phastcall

Thanks Ken,
That makes perfect sense. I was hoping to isolate the circulator and flip it around, at the risk of reverse flow through taco valves. I know this sounds hackish, but tight location, friend of a friend, who spent all his money,well you know.

Gene_3

just make sure

that your exp tank is behind the circ, if in front of the flow the circ will push the diaphram instead of the water, dig?

mark smith

why not repipe this the RIGHT way .....

spent All his money ....

yea, on what ...somebody's Sidejob ....????

stop charity now ...

he didn't give You the job .. Right ..??

big bob

answer from experience

you absolutely need to repipe return to bottom.the only reason i say this is because we have a plumber in my area who is excellent with plumbing.but not a heating guy he did the same thing you speak of.i called the boiler manufacturer to make sure it could be done that way and they said absolutely not.because it will not only rush the aquasta but that it also surges faster into boiler.from top due to increased spacing internally at the top of the boiler.thus swinging boiler temp faster and shocking the block.they requested that i change the piping to bottom and rework setup.i did so and have never heard from customer about hammering or knocking again.