Weil McLain ECO 70. Odd sound.

djc2232

Just finished cleaning Inside my heat exchanger with water and soft brush. Got it all nice and clean and got it back together just fine. 

I fired it up, purged and ignited just fine. When it ramped up to 65% I could hear a slight hissing sound from the heat exchanger. If I covered the blower intake, the sounds went away. When the blower speed got below 65% or around there it was normal. No sound.  

Only thing I could see it being is that I didn't tighten the igniter down enough or the heat exchanger cover plate. I don't have a torque wrench and didn't want to tighten that stuff down too far. The Manuel says for the exchanger cover no more than 45in lbs. The igniter is no more than 20in lbs. 

Any idea?  Will be picking up a torque wrench this week to get those bolts where they need to be and hope it solves the problem. 

Solid_Fuel_Man

Is the hissing sound like water almost at a boil in a kettle? 

djc2232

Kind of. I would say between that and a little bit of water on a hot fry pan. Boiler is going on it's 4th winter so it's still pretty new. Cleaned out the hx pretty good with just water. It sounds perfectly normal when blower speed is below about 65%. Which is about 98% of the time its running during the winter. 

djc2232

I unfortunately don't have a combustion analyser. Could the gas/air mix benoff causing it to be running a little lean at that higher percentage causing the hissing?

Solid_Fuel_Man

Mine does the same thing, burned about 1200 gallons of propane since new 3 years ago. I'm going to try running Sentinel X200 boiler cleaner through it and see if it clears it up. I wonder if the noise is due to mineral deposits on the water side. 

flat_twin

OK, I'm curious if the sound is really kettling or a leak at the HX gasket when the fan pushes above 65%, especially when you went easy on those four nuts without a torque wrench. New gasket, old gasket? Did you break down and clean the burner assembly? Condensate trap cleaned and running clear? Any chance air was introduced to the system? Was the water side of the HX opened for any reason. Any chance the circulator speed was changed /reduced?

djc2232

Water is pretty darn clean and tests right in the range for the inhibitor. Condensate trap was removed and cleaned. Usually do that once in the middle of the heating season too. Didn't clean the burner itself. Looked pretty good. Cleaned and flushed the hx till it ran clean. Got all the deposits off. Water side wasn't opened at all so sir shouldn't have gotten in. When it does I hear it purge out. Water psi is right at 12 where it usually is. Fan speed wasn't changed. Took off the silencer and whiped down the dust that had accumulated in it. Other that that it was unchanged. 

Only new gaskets were for the igniter and the hx plate cover that were taken off. As of right now it points to the bolts for the hx plate cover and the igniter bolts. When I took them off they were torqued down pretty good from last time tech opened it up. Going to grab a torque wrench this week sometime and try that in hopes it fixes it. If not, call to my hvac company to check combustion numbers. 

Everything else is normal sounding. Pre purge, ignition, heating, shutdown and anything below 65-70 percent speed. 

djc2232

Right now I believe it's a small leak at one of those two gaskets when the fan really ramps up sucking air it starts coming in through a small gap somewhere then stops when I cover the air intake with my hand. Surface was pretty darn clean  when I placed the new gaskets too. 

mattmia2

You could put a little water at the spot you suspect is leaking, it will likely seal or slow a small leak.

The bolts likely were not torqued down that hard but had seized from the different metals involved.

djc2232

Bolts arent seized. Came out just fine and went in just fine. I torqued them down to where I thought they were when I took them off.  They are snug but I can definitely tighten them more.  

djc2232

Slight hissing sound that is above a certain percent?  Mine rarely ever gets that high anyways and if it does it isn't for long. 

Just picked up a torque wrench set that will be in next week. Will report back when I get those bolts where they need to be. Solid_Fuel_Man said:

Mine does the same thing, burned about 1200 gallons of propane since new 3 years ago. I'm going to try running Sentinel X200 boiler cleaner through it and see if it clears it up. I wonder if the noise is due to mineral deposits on the water side. 

Solid_Fuel_Man

I have mine throttled to 3200 RPM. above that it kettles, didnt do it when new. Flow has been confirmed and is well above what the chart says, cant remember the numbers off the top of my head. 

djc2232

Yea I believe the 70 and 110 blower rpms are different but my max is set at 4150 and min is 1100. Those are factory defaults for the 70. Mine never did it new either. Just started after I cleaned out the hx myself. Never did it when my hvac tech cleaned it though so I'm guessing it's the bolt torque. The tech who did the cleaning last really had them tightened down good. 

But when it first fires and the blower is around 70% before modulating down there's no his. It's only when it initially starts to modulate back up when it starts to his. Tuesday my torque wrench will be in I ordered so we will see. I'm not too worried as it's rarely at that percentage very much. It's usually around mid 40s and below. 

djc2232

Comparing the sound from mine to an actual kettling boiler it's definitely not that. 

djc2232

Well got the igniter bolts and cover plate bolts torqued down to where the manual says. Still getting the hissing around 60 % blower speed and higher. Going to give my hvac company a call and see if they can check the combustion numbers. May pick up a few extra gaskets and change those out again and see if that helps. 

JUGHNE

Any leakage on the trap drain under the boiler?

flat_twin

Can you post a video/audio clip of the hiss?

djc2232

JUGHNE said:

Any leakage on the trap drain under the boiler?

Nope. Nothing I can see. And the trap below outside the boiler is draining properly. Plus when I flushed out the HX with a bunch of water it was dry as a bone down there.   Id hate to try and tighten the bolts any more than what the manual states. When I took them off they were tightened down pretty good. More than what the manual says i feel. 

I'm wondering if I messed up the gasket for the igniter or cover plate some how causing an air leak?  Can't see the air fuel mixture going weird after only 3 heating season. The Inside of the hx is pretty darn clean now compared to what it was 

JUGHNE

If you shut off the water fill valve, will the pressure eventually drop?

djc2232

flat_twin said:

Can you post a video/audio clip of the hiss?

Sure. I'll take a short clip and post it here what I can.  

djc2232

JUGHNE said:

If you shut off the water fill valve, will the pressure eventually drop?

Didn't try that. I can but I don't think it's water related. And when the auto fill kicks on it's pretty noticeable and it hasn't the times I've had it running. The sound is blower speed related and when it's above 60-65%. When it's hissing and I cover the air intake slightly it stops making the noise. Which makes me believe it's air/fuel related. Wether the air/fuel is off when at that speed or there's a small air leak still somewhere. 

djc2232

Short clip just uploadex

djc2232

Here's a YouTube link if the Google photos app doesn't work. https://youtu.be/yYZFHLCoA68

djc2232

Solid_Fuel_Man said:

I have mine throttled to 3200 RPM. above that it kettles, didnt do it when new. Flow has been confirmed and is well above what the chart says, cant remember the numbers off the top of my head. 

Mine never did it new either. I've had my tech open it up after the first season heating to check and swap igniter but it never made this noise. Only after I opened it last week and flushed it with water and scrubbed the hx to get all the crud off, swapped the igniter and changed the gaskets. I have some new gaskets arriving I may change out and see if that's the issue and going to have my tech check the combustion numbers. Wondering if it's leaning out on high fire some how when the blower really ramps up. 

djc2232

https://youtu.be/q8E5syU3vuo

Here's a short clip of it ramping down and the sound going away. It's very rare that the boiler is at that percentage causing the sound anyways. 

djc2232

HVAC tech came out and took a look. Combustion numbers all look good. Ran a sniffer around and didn't detect a leak so the gaskets should be good that I replaced. 

He did mention the primary boiler pump which is a taco 007 felt pretty warm and may be gummed or running slow causing a lower water flow. And now with a clean exchanger the lower water flow causing some water to boil at the higher temps/blower rpms. 

Just odd that a new pump could already be bad. I haven't decided yet if I want to change the pump and see if that solves the problem. 

SteveSan

A Taco 007-F5 will draw about .72 amps if operating correctly. The temp range on the motor is about 140-160 degrees under normal conditions so they do run "hot". I would suggests an amp reading and they will let you know if the cartridge assembly is running "slow" or you may have air in the system.

djc2232

SteveSan said:

A Taco 007-F5 will draw about .72 amps if operating correctly. The temp range on the motor is about 140-160 degrees under normal conditions so they do run "hot". I would suggests an amp reading and they will let you know if the cartridge assembly is running "slow" or you may have air in the system.

That was checked as well. He said everything looked good as far as the electrical go on the pump. 

djc2232

Auto feeder was checked and is operating correctly. Pressure was increased just a tad to about 17psi. Normally at 10-12. Drained about half gallon of the water and it's pretty clear as well. No discoloration or debris. 

May try to flush out the water side a bit with some cleaner before buying a replacement pump. 

djc2232

Solid_Fuel_Man said:

I have mine throttled to 3200 RPM. above that it kettles, didnt do it when new. Flow has been confirmed and is well above what the chart says, cant remember the numbers off the top of my head. 

How do you check the flow rate?  My boiler circ is just a standard 007-f5. 

Solid_Fuel_Man

I confirmed flow by calculating pipe volume and timing how long it takes for the return to cool off. Mine figured out to be just under 10gpm. That was with a Taco 0015 on speed 2. The boiler is piped primary/secondary. 

Get the entire primary loop hot, then open ball valves to loads which are calling. 

Solid_Fuel_Man

Also, I've replaced my indirect and made some piping, circulator changes, and added a Caleffi dirtmag. I tested my local well and it is 15 grains of hardness. Last I tested it is was 9 grains. The drought this summer has caused lots of things to change with our water locally. 

I'm sourcing some DM water to refill my system now that parts have been drained. 

I dosed the correct amount of X100 after using Sentinel system cleaner when I commissioned the system a few years ago. 

I have a large volume system with a wood boiler and a cast iron zone as well as radiant slab. 

djc2232

I just can't see a taco 007 f5 going bad after only 3 years. It's a fairly small system with only two zones, one floor  Our well water here is pretty good. I have never tested it but my observations with my other appliances leadse to believe it's pretty clean.

Tech recommended changing primary boiler circ pump and flush the system. Just not sure what else I could try before going that route. I'd hate to replace a pretty young pump. Everything points to it being ok. But who knows. He did close a valve on the return just near the pump when it was running and I believe you should start to hear the "woosh" sound of the water as soon as you so. He was closing it slowly and it didn't start till a little bit after he turned it. 

I may just let it run for bit and see how it does as it it's rarely ever runs at that percentage and higher. Those taco pumps aren't very expensive anyways. Just not sure what else it would be. If I change it out and have it flushed and that doesn't solve it at least I'll have a spare pump for when it really does. 

djc2232

It's just odd that flow would be impacted with this new of a system. The hx was cleaned quite well which makes me think that since it's getting a better transfer of heat, when the burner operates at a higher percentage it's vaporizing some water. It didn't do it before when it was new but maybe it just took a few years for the primary pump to get a little gummed up reducing flow. Amps on it seemed ok though. 

Solid_Fuel_Man

Mine did the same thing. 

It's the water side, either lack of flow (which you can check the same way I described), or water quality. 

No way to tell unless you test/have your water tested. 

I use a boiler water test kit made by Taylor to check total hardness, p/t alkalinity, and chloride, as well as litmus paper for Ph.