New home, older boiler

mrd1995

Good morning everyone,
My Wife and I just purchased our first home in beautiful snowy Erie County, PA. I knew going into the purchase that the boiler was probably the most risky part of the purchase, it is a Weil-Mclain VHE-6 hot water condensing boiler, I believe the name plate stamp is dated 1983 or 1986. It is feeding a four zone system, (2 zones in the basement and 2 on the first floor).

After the closing on the house the prior owner did stop and show us some of the critical points on the system, propane shut off ( no Nat. gas lines), water shutoff, etc. He also had a local contractor come out and service the system. Two weeks have gone by and now we are getting some gurgling air noises in the first floor baseboard radiators. I called the contractor and asked about the noise and they said that I may have to add a little pressure to the Fill-Troll w. Extrol supposedly he adjusted it when he serviced the system. Since then I have found that the pressure relief valve does have a few drips of water, the float type air vent is missing the cap and who ever installed the system did not include isolation valves of the hot side of the boiler only the Honeywell zone valves. Also by depressing the valve stem on the bottom of the expansion tank I do not get any air or water by doing so. So what ever I do is going to be a mess. Here are my questions concerns,

-could adding a little air to the bladder help dislodge the air bubbles?
- The bigger question, why would I be getting air into the system could it be from the addition of water due to the dripping RV?
- The Fill-Trol, Expansion tank, and air vent look to be all original, should I just replace the whole thing and not even bother trying to adjust the air pressure?

Looking forward to your responses, this is the first time I have dealt with any hot water boiler issues.

STEVEusaPA

If you got the money and/or time, it wouldn't hurt to do a little upgrading to your near boiler piping.
The air scoop is relatively ineffective for removing air, it's older technology, as well as the fossil on top of it.
If you do a repipe, new air eliminator (microbubble resorber), webstone expansion tank valve, pump away from expansion tank, and put in the proper valves for circulator, component replacement, and purging.

Expansion tank has either lost it's charge or has failed. It needs to be isolated and removed from system to check charge. Then you could try to pump it up and see if it holds, or replace it.

mrd1995

@STEVEusaPA thank you for your response. I am actually going to do a complete new system come spring/summer, the boiler has been in service for 36 yrs running well water. I was hoping to just replace/fix/band aide the expansion tank and fill-troll till summer rolls around, I already have two quotes being put together by local Heating companies for a new boiler and domestic hot water supply, as well as a salt-free water conditioning system for the whole house( We were under the impression hard-water was not present, we believe the owners had professional cleaners come in remove evidence of the scale).

mrd1995

I'm assuming the air scoop, the float air vent and other components are scaled up badly.

Jamie Hall

Sounds like you have a decent plan for the future. Is there a pressure gauge on the system? And, if so, what does it read when the system is cool or cold and when it is nice and hot? The fact that you get no water when you depress the Schrader valve on the bottom of the tank is at least vaguely encouraging. The fact that you don't get any air either is vaguely discouraging -- either there is no air in there to get, or the valve isn't working. Get yourself a bicycle pump with a clip (makes it easier!) and try to see if you can persuade any air to go into the tank. Try for around 12 psi when the system is cold and see what happens. It's not the best way to recharge a tank -- but since you have no handy dandy isolation valves, it's a decent first try.

mrd1995

@Jamie Hall, Thank you for your advice. I will give that a try tonight and let everyone know how it goes. I may pick up a spare fill-troll kit before trying it though, I have a feeling this is going to be one of those situations that you try putting a little air and then the whole system collapses due to one small change. I hope I am wrong but I would rather be prepared and only get wet once!

mattmia2

You are getting air in the system because you are losing and adding water to the system when the system heats and cools because your expansion tank has no charge in it. The air is the air that is dissolved in the new water.

If you plan to replace the system I would just charge the tank and see if it holds. To charge the tank:
1. Note what the system pressure is with the system cold and the shutoff to the fill valve open.
2. Turn off the boiler so it doesn't fire during this process.
3. Close the shutoff to the fill valve
4. Connect a bicycle pump to the air valve on the expansion tank
5. Open a drain on the boiler and let out water until the pressure in the system is 0. Leave the valve open to remove the pressure you add as you pump up the tank.
6. Pump up the tank to the pressure you recorded with the system cold.
7. Close the drain, remove the pump, and turn the fill valve back on.
8. If necessary purge or bleed the system if you have introduced enough air that the system isn't circulating. If the system is circulating, the air should migrate to the air scoop and be removed there.

Check that there is a charge in that tank and that they relief valve is no longer opening. If the tank isn't holding a charge then you will have to replace the tank.

The cap on the automatic vent is only for service. It need to be open for it to function, that is where it vents any air it accumulates, usually through the cap that is partially loosened, but it will work fine without the cap as well.

mrd1995

@mattmia2 Thank you for your instructions.

mattmia2

BTW, the system pressure could should be around 15 psig. The relief valve is probably 30 psig and it is probably sitting at that pressure when it is hot now because the expansion tank has no charge.

mrd1995

I checked the pressure gauge while the system was running, was only at 20 psi. Not sure why but I decided to grab ahold of the RV drain hose and it was warm and had flow. Picked up on the manual relief handle and there was no tension from the spring. So the valve and I believe the fill-troll is completely shot. Only good news is that we have a 1 yr home warranty which covers the radiant heating system so I am curios what the responding contractor tells us. I am truthfully hoping he tells us the system needs replaced. Thank you once again for the advice.

JUGHNE

This should be a good test for the experience of a home warranty company. Please keep us advised.

jimna01

Good luck with the home warranty company. They usually send the lowest bidder. As for replacement remember careful what you wish for. Most how warranty companies will only pay you for the depreciated value of the equipment not the entire cost of a new one. And normally you get zero choice in the replacement equipment .

mrd1995

Update, contractor came out yesterday afternoon we replaced the float style air vent and the PR Valve. Filled the system and started to bleed the lines, I knew something was up the contractor seemed confused so I asked. The hot side and the return was hot but not the pipes in between or the Radiators. Plus we were not getting air, after about 1.5hr of playing with the blenders he decided to check the circulation pump and it seemed to be running CCW then switching to CW and then back. So that is today's venture plus had an elbow start to leak at a past contractor or homeowners custom shrader valve air bleeder looks like off of an AC unit purge. So we are redraining cutting and replacing elbows did not see them prior to buying the home they were tucked into some tight places throughout the system.

mrd1995

Also my mind is sort of at ease with the contractor, I asked about replacing it in the future and said honestly it's good shape for 36yr in service of course minus what is not working currently.

mrd1995

Contractor came and went did what they could with the warranty coverage. So far so good we cut out 7 of the shrader valve blenders all except one were above the basement drop ceiling. Ended finding two that were leaking plus we replaced the PRV and the float air vent, added isolation valves. Biggest thing for me besides stopping the leaks was that I learned a lot about the zones and layout of them. I could not figure out prior to this why the cast Radiators never got to hot to touch! Well pretty sure they are plumbed incorrectly, basically the supply line is continuing ours thought the whole basement, two Ts were added per Radiator so there is not a true flow path it's more stagnant conduction through the water column. Hope this makes sense would love some input and thoughts to why it was done this way. Come Spring time I plan to correct this so we have a true supply and return circuit.

bobby32x

Sorry to hijack this post, but I read that you need 18" of straight away for the air scoop to work effectively. If I put mine in a spot where I have 18" of straight run, the turn will pretty much be directly after that in order to plumb up to my piping that leads to each zone circulator. Is it ok to have a turn directly after it? I saw a diagram noting the 18" beforehand but not anything really describing the downstream piping.

heathead

Please read about monoflow tee’s.. That is what you described. That should be the tees that get heat to the radiators. It will make it easier to see how it’s piped. Do you have the air out of the individual radiators. Hopefully someone can expand on this. Tying to point you toward help, hopefully someone else will chime in. Good luck.