Weil-Mclain VHE Boiler noises

Tony_23

Just don't think I can help you. If he cut the SS, I would say you're screwed. Maybe there's a Propress fitting that'll fit, the SS may be copper tube size OD.

tbar0000

Weil-Mclain VHE Boiler noises

I have a VHE-5 Series 3 boiler, and have a strange problem. Ever since my VHE was moved into the basement- I have noticed a strange "boing" (for lack of a better word) sound coming from it only when the boiler first starts up. When the boiler was re-located, the plumber cut out the piping going to the secondary heat loop at the rear of the boiler saying it was unnecessary. Since then I have had this expansion/oil canning sound problem. I assume that the removing the secondary loop from the system caused the temperatures of the 2 (fore and aft) sections of the boiler to be heated up at different rates, causing the metals to expand and a boing sound occurring. This only occurs when the boiler water temp goes from low to high temp. All is perfect (and quiet) once it heats up. It never happened before it was relocated.

I would like to re-connect the secondary loop and hope that someone could take a digital photo of the plumbing side of the VHE and possibly emailing it to me. I'd like to see how yours is plumbed as I would like to set it back to the condition it was before it was relocated.

Any help would be greatly appreciated.

Tom

J.C.A._3

Sounds like....

He removed a system by-pass. This would temper, by moving some of the outgoing water back into the boiler to prevent both condensation and the "boing" noise you are hearing.

My guess would be that the inserted plates between the sections are springing when the boiler is firing from cold. Chris

Jason_15

VHE

The VHE series from the 1980's had a secondary heat exchanger made of(I believe) copper fin tube after the cast iron heat exchanger to squeeze the AFUE rating up to 87.5% I still have one of these running in my basement. It doesn't sound like there are too many of these left out there. Has anyone seen one of these lately? Mine has had it's share of issues- I'm hoping to replace it this summer. It is amazingly efficient for something 23 years old, it just isn't reliable.

Tony_23

VHE

That secondary loop recovers heat from the last part of the exhaust train into the return water before the CI section of the boiler. Coolest water/hottest gases. My guess is your CI is seeing consistently cooler water than it typically has throughout it's life and the noises you're hearing are expansion noises.

I'm also going to say that you've lost a good portion of your boiler's HX surface and hence, capacity.

tbar0000

System Bypass

Yep- sounds right, Looking at the VHE boiler manual it appears to be listed as bypass piping. I did not notice this before. Problem is there are 3 illustrations for 3 different methods of plumbing this. I'm guessing it should be plumbed as in the 2nd figure (protection from condensation from lo temp return water), the other 2 illustrations are mainly for bypassing to protect radiant panels, plaster etc from high temp water. No radiant ceilings or anything like that here- just baseboards.

In the plumber who removed this piping's defense- The manual states that "bypass piping is not normally required on any baseboard system". But as I remember the plumbing wasn't really bypassing the boiler- more like preheating the return water before the boiler gets it.

Tony_23

It is NOT

A bypass. The manual is referring to piping external to the boiler. The secondary coil you are referring to is considered internal to the boiler.

tbar0000

Your correct

You're right. It is not a bypass- I do see the error the plumber made and should be able to correct it using the drawings from the manual.

Thanks for the help,
Tom

ken from nw ohio_3

He effectivley made an HE out of your VHE. Dropped the efficiency from 85% to 80% if I remember correctly. We have quite a few VHE's still running.

ken

tbar0000

VHE saga continues

Tech question continued… A plumber moved my VHE boiler and in the process replumbed it effectively taking the rear heat exchanger out of the system (sort of making it a HE instead of a VHE). Problem is it needs to be put back to normal configuration as the 2 sections are expanding/contracting at a different rates causing large BOING noises (for lack of a better word), not to mention the reduction in efficiency. Original plumber will not respond to my calls to fix this! Other local plumbers state that they cannot get the proprietary o-ring type copper fittings that attach to the secondary heat exchanger (stainless)piping and are afraid to try and sweat the current fittings due to the cut section of copper pipe is too close to the Orings. Questions:

Can these fittings be replaced? How to remove them? (are they pressed on?) Can I get parts? Where? If I can't then I will have to spend thousands on a new boiler for someone else’s mistake! This boiler otherwise works great and is 87% efficient when hooked up properly- good enough for me! Any info will help greatly.

Thanks in advance,

Tom Barsch

tbar0000

Stumped the masses?

What, has no one heard of these O-ring sealed fittings on the rear heat exchanger on the VHE boilers- This is looking very bad for me.

Weezbo

Boing is not good *~/:) Trust me on this one

maybe an expansion compression fitting is in order....not cheap buh definitely along the lines of a dresser coupling (no Heat) connection.