[BurnerGuy]

Hi All,

What is everyone's position for cycling the pressure relief valve when performing PM's / Tune ups on a resi boiler? I always check them because of it being a critical safety factor, but I often find that when i do cycle them they don't always reseat and sometimes need to be replaced. I personally haven't ever found one that has failed, but it just helps me sleep better at night.

The question came up today because i had a HO tell me that I broke it and it 'didn't leak before' and accused me of charging them for something they didn't need. :gah:

I am now thinking of having the customer choose if they want me to check it, but let them know it may need replacing once checked. If the refuse, i'd probably make note of it in my tune up report.

what is your standard method of operation for this?

Thanks!

 

[jmac00]

Generally speaking, I replace them every five years. I just tell the customer it's a cheap easy thing to replace when the system is down for maintenance and it's only $ and it's better to do it now than when it's minus 5° plus, later there will be a service call added.

it's really an easy sell, if you use humor to sell it: "I can replace this later, but you know when this thing is going to crap out......about 10am Christmas morning" <big stupid grin>

works almost every time

 

[pcp]

I found one failed recently. Plugged with sludge, the boiler drain was also plugged. The boiler was filled using well water with no treatment.

 

[jmac00]

I found one failed recently. Plugged with sludge, the boiler drain was also plugged. The boiler was filled using well water with no treatment.

gezz, not even a filter? thats nuts

 

[STEVEusaPA]

I thought by code you are suppose to exercise them every year. I tell the h/o basically this before I touch it:
This is one of the most important safety features on your boiler, the pressure relief valve. I go on to explain what it does/why it needs to be exercised. I then go on to explain that sometimes when you check the valve, it wont reseat properly and will need to be replaced. Then I pop it right in front of them.
I've never had anyone accuse me of breaking it after this.
Also you can give it a medium (your definition) tap on top of the stem to reseat them and stop the drip.
The worse one I had is when I lifted the lever and the whole valve broke. Luckily there was some shut off valves, and it was an unfinished basement...and the boiler was cold.

 

[hvacker]

If you don't trip the valve you'll never know if it's plugged. Trip the valve, shut off water, blow down the expansion tank, If it's a bladder,check air pressure, restore water pressure. This way you'll be testing the PRV at the same time.
This was just my approach. I know there can be some hesitation because sometimes the valve won't seat but ya gotta find out.

Too bad about the customer accusing you.Maybe what STEVEusapPA suggested, have the customer witness the trip.

 

[displaced texan]

Test them. Otherwise, you will not know if they work. I have found plugged discharge lines on several occasions and at least twice have found the maintenance man capped the discharge line to stop the drip!! My preferred method of testing is to raise the boiler pressure until the valve opens and see if it is at design pressure.

 

[Cbssteve]

Have to check them. I know up in NYC plumbers will have customers close there main valve coming in if the valve is old or in rough shape. If it valve won't open from stem failure, or starts leaking when they touch it, it's not the plumbers fault. Just food for thought.

 

[ch4man]

a working relief is best described as one that doesnt leak before you touch it, opens when you exercise it and fully closes after. and of course opens when exposed to pressures exceeding its rating

test them. if it leaks after you exercise it, then it failed the test of "a working relief" and needs to be replaced, you tested, it failed.

but yes, explain this first to the HO

 

[trottier]

Test them. Otherwise, you will not know if they work. I have found plugged discharge lines on several occasions and at least twice have found the maintenance man capped the discharge line to stop the drip!! My preferred method of testing is to raise the boiler pressure until the valve opens and see if it is at design pressure.

stupid question.. how do you raise the boiler pressure? just with the pressure reducing valve?

 

[jmac00]

stupid question.. how do you raise the boiler pressure? just with the pressure reducing valve?

you don't, you need to add water via the fast fill valve till you reach 30lbs, but this will generally leave a mess on the floor, even if you put a bucket under it, the force from the discharge will be violent and splash water everywhere

 

[trottier]

Thx jmac. Hvacker... What do u mean blow down expansion tank??

Sorry for the lame questions guys but I'm starting to work on these more but not really getting the direction from home.

 

[jmac00]

ok, most residential Hydronic boilers do NOT need to be "blown down" It's just not necessary. although a good short drain at the beginning of the season wouldn't hurt, and then do a fast fill just to 'shake things up" and then do another quick drain and refill ( I guess you could call that a blow down???)

However, residential STEAM boilers ( in reality all steam boilers) should be "skimmed" at the beginning of each heating season. any accumulation of dirt that sits on top of the water creates a barrier to making steam. You will know the water is contaminated because the boiler will be "surging" and the water in the site glass will be bouncing up and down like a yo-yo (NOT GOOD) you can add chemicals to break up the debris, but a good skimming works just as well~~~IMHO

"blown down" basically means that you open the boiler drain and let some water out, while it's running, this gets rid of or 'dumps' any debris (dirt--rust) that accumulates in the bottom of the boiler or the return lines.

Residential steam boilers work, mainly on gravity (at or near zero PSI, but less than 2psi) Think of a three inch pipe, you're looking down the end of the pipe. The top half of the pipe will be steam, the bottom will be condensate (water), the return lines are all condensate. But if the system was installed correctly ALL the steam lines should slopped back to the boiler. if the steam boiler is working at zero psi, any debris in the system will be washed to the return lines where it will drop to the bottom of the pipe because the Hartford loop will prevent the debris from raising back into the boiler.

ok, I have been typing for 10 min and didn't realize I went into lecture/diatribe mode...LOL sorry Hope this helps

 

[trottier]

Yeah Thx jmac. That's awsome. That all makes sense. I guess some of it for me is the terminology. Lol.

 

[Poodle Head Mikey]

That steam piping scheme (steam piping pitched Towards the boiler) is true for a bi-flow-main system. But an alternative arrangement is to pitch all the supply piping Away from the boiler and drain the condensate out the far ends into wet-leg returns.

PHM
----------

. . . Residential steam boilers work, mainly on gravity (at or near zero PSI, but less than 2psi) Think of a three inch pipe, you're looking down the end of the pipe. The top half of the pipe will be steam, the bottom will be condensate (water), the return lines are all condensate. But if the system was installed correctly ALL the steam lines should slopped back to the boiler. if the steam boiler is working at zero psi, any debris in the system will be washed to the return lines where it will drop to the bottom of the pipe because the Hartford loop will prevent the debris from raising back into the boiler.

ok, I have been typing for 10 min and didn't realize I went into lecture/diatribe mode...LOL sorry Hope this helps

 

[buttwheat]

Yes always blow down the pressure relief valve it tests it and clears the sediment that is building up in it to keep it clear. (never do it on a Friday afternoon)
It is part of the testing procedure of any boiler that needs a yearly inspection license.

 

[Poodle Head Mikey]

Brilliant! <g>

PHM
------

Yes always blow down the pressure relief valve . . . (but) never do it on a Friday afternoon . . . .

 

[BurnerGuy]

That steam piping scheme (steam piping pitched Towards the boiler) is true for a bi-flow-main system. But an alternative arrangement is to pitch all the supply piping Away from the boiler and drain the condensate out the far ends into wet-leg returns.

PHM
----------

LOL The friday afternoon was my scenario! and to make matters worse, i thought i had one more valve on the truck, but it was 1/2", not 3/4".

had to make a run back to the shop just for the stupid thing. That's what drove me to question if i should even bother. I appreciate all the feedback!

 

[ch4man]

ok, most residential Hydronic boilers do NOT need to be "blown down" It's just not necessary. although a good short drain at the beginning of the season wouldn't hurt, and then do a fast fill just to 'shake things up" and then do another quick drain and refill ( I guess you could call that a blow down???)

However, residential STEAM boilers ( in reality all steam boilers) should be "skimmed" at the beginning of each heating season. any accumulation of dirt that sits on top of the water creates a barrier to making steam. You will know the water is contaminated because the boiler will be "surging" and the water in the site glass will be bouncing up and down like a yo-yo (NOT GOOD) you can add chemicals to break up the debris, but a good skimming works just as well~~~IMHO

"blown down" basically means that you open the boiler drain and let some water out, while it's running, this gets rid of or 'dumps' any debris (dirt--rust) that accumulates in the bottom of the boiler or the return lines.

Residential steam boilers work, mainly on gravity (at or near zero PSI, but less than 2psi) Think of a three inch pipe, you're looking down the end of the pipe. The top half of the pipe will be steam, the bottom will be condensate (water), the return lines are all condensate. But if the system was installed correctly ALL the steam lines should slopped back to the boiler. if the steam boiler is working at zero psi, any debris in the system will be washed to the return lines where it will drop to the bottom of the pipe because the Hartford loop will prevent the debris from raising back into the boiler.

ok, I have been typing for 10 min and didn't realize I went into lecture/diatribe mode...LOL sorry Hope this helps

yes,, well no.....:.02:

a steam boiler blow down is the clearing of any and all float type LWCO's to keep them mud free, insure the burner shuts off and then therefore safe. this is the most important blown to be done.
surface and bottom blow downs are still good, dont get me wrong, but maintanance of the safeties is of the utmost importance

 

[jmac00]

yes,, well no.....:.02:

a steam boiler blow down is the clearing of any and all float type LWCO's to keep them mud free, insure the burner shuts off and then therefore safe. this is the most important blown to be done.
surface and bottom blow downs are still good, dont get me wrong, but maintanance of the safeties is of the utmost importance

good point