Plumbers / HVAC people?

bobman1235

I have an oil-fired forced hot water boiler in my house.

There are three zones : basement, first floor, second floor.

Second floor and basement heat work fine, so the boiler seems to be heating the water correctly. First floor if I turn on the thermostat I can hear the circulator kick on, if I go down to the furnace I can feel it humming... but it's HOT. LIke, REAL hot. And not doing its job, as all the baseboards and pipes leading to the first floor are cold. So... is my circulator dead? Is there a possible other explanation (ie just need to bleed the lines)? How hard is it for an amateur to change a circulator? I've done some basic plumbing in the past, and am pretty resourceful, but am I getting in way over my head? I'd just rather not pay a plumber 400 dollars or whatever they'd charge for something I could do myself.

nadams

So there's a separate circulator for each zone? Or do they all run from one circulator? Like you said, could be air in the lines... is there a valve on that loop that you could crack open (carefully) and see if you get water? Beware, though... when I opened the drain on my water heater, it wouldn't close properly, and I ended up having to replace the shutoff.

bobman1235

Correct, each zone has its own circulator. When the thermostat kicks in, all it's really doing is turning on the circulator for that zone.

Each zone also has a drain / bleed valve right above the circulator. There's several shutoffs (one before and after each circulator, which is on the return side, and also one on the feed for each zone) so even if the one valve gets "stuck" it won't be too disastrous.

System looks like this :

Demiurge

I think we found the problem, there's a giant **** blocking the water flow.

MillerLiteScott

Can you tell if the circulator is turning? If it is not turning it may have something jammed in the impeller or the bearing siezed and it is not pumping your water. See if it sounds different than the other circulators.

My 2 cents.

Scott

disneyjoe7

Demi, you got that right.

mrbigbluelight

Several possiblities (not knowing the exact layout):

1. Circulating pump.
If it isn't possible to visually see if the pump is turning, and that's most
likely the case, does the level bounce at all in the expansion tank when
the circulator kicks on ? You should see some bounce.

2. Stuck check valve. There should be check valves in each loop, to
prevent backflow from the other loops. Possible that a check valve is
calcified up and sticking closed.

3. Zone valve not opening. Not sure if the 3 loops are totally separate or
if they share common headers with the loops being isolated with zone
valves. If so, when the T-stat calls for heat, the circulator starts and
the zone valve for that loops should open. If it doesn't, than no flow and
no heat.

4. Pump air bound or dropped impeller. Don't think this will be the case if
the pump is located as diagrammed (in the vertical loop).

5. Poltergeists. Torch the house and run for you life and do not leave a
forwarding address (of else they'll find you).

BaggedLancer

I had my suspicion and just asked my dad to confirmed but he said 90% chance if it hasn't been used in a while it's airbound and you should purge the system.

If it's not airbound it could be any number of things from the circulator to the valves.....check to make sure the zone valve is open(sound trivial but you'd be suprised).

bobman1235

mrbigbluelight wrote: »

Several possiblities (not knowing the exact layout):

1. Circulating pump.
If it isn't possible to visually see if the pump is turning, and that's most
likely the case, does the level bounce at all in the expansion tank when
the circulator kicks on ? You should see some bounce.

2. Stuck check valve. There should be check valves in each loop, to
prevent backflow from the other loops. Possible that a check valve is
calcified up and sticking closed.

3. Zone valve not opening. Not sure if the 3 loops are totally separate or
if they share common headers with the loops being isolated with zone
valves. If so, when the T-stat calls for heat, the circulator starts and
the zone valve for that loops should open. If it doesn't, than no flow and
no heat.

4. Pump air bound or dropped impeller. Don't think this will be the case if
the pump is located as diagrammed (in the vertical loop).

5. Poltergeists. Torch the house and run for you life and do not leave a
forwarding address (of else they'll find you).

As far as I can tell, nothing separates the zones aside from the circulating pumps - no zone valves etc. Below are pictures of both ends of the loops. From the boiler, it goes to the expansion tank directly into a straight pipe with the three loops attached and nothing between them. On the return, each loop has a faucet (for bleeding air I assume), a circulating pump and shutoff valves, and then they feed into the same return pipe into the boiler, again with no valves in between.

The return side, with pumps :


Feed side, with expansion tank :

disneyjoe7

Ok I have a question for ya.

The zone which doesn't work does the motor of the circulating pump warm? As it has power but is frozen. I think you need to answer this question first does the pump get power when heat is called for. Answer this question so you know if its the pump or something that controls it.

bobman1235

The pump does indeed switch on when the thermostat is switched on, and switches off when the thermostat is off. The pump sounds like the other two (kind of a faint buzz, like a pump sounds), but gets significantly hotter than the other two. Doing some googling on the pump (a Taco 007 series) apparently they commonly get very hot, but it's still suspicious - it literally hurts to touch it after it's been going for a few minutes.

BaggedLancer

Edited

disneyjoe7

Ok so I my thinking is that something has frozen pump, so either rebuild pump or replace it. Whatever is cheaper or less trouble, our call.

mrbigbluelight

From the pictures, there are no check valves in the system.

Looks like common discharge/suction headers, so the only thing separating the 3 zones are the zone valves.

Each pump does NOT pump to a separate floor/zone.
The system looks like each pump stages on when its Tstat calls for heat.

For instance:

If the 1st floor calls for heat, the 1st floor zone valve opens, the 1st floor pump (we'll call it that) comes on, and hot water flows through the 1st floor zone valve to heat the 1st floor.

If, at the same time, the 2nd floor calls for heat, the 2nd floor zone valve opens,the 2nd floor pump (we'll call it that) comes on, and hot water flows through the 2nd floor zone valve to heat the 2nd floor.

Ditto, the 3d floor.

The ONLY reason you have 3 pumps in the system is to supply additonal flow as each zone calls for heat.
The SAME water flows through each zone; there are no separate water loops (they do run in parallel, though).

That's an important distinction and here's why:

If TWO zones are calling for heat, TWO zone valves open, and if only ONE pump comes on, each zone will get half the flow.
You WILL get heat at each zone, but at a reduced level.

If TWO zones are calling for heat, ONE zone valve opens, and TWO pumps come on, one zone will not get any heat (zone valve stuck closed) while the other zone gets all the flow and a lot of heat.


To check this guess, do the following:

1. Turn all the Tstats down to 55 % F (or their lowest setting).
This is to make sure all zone valves go closed, all pumps off.
2. Let the piping cool down (give it an hour or so).
You're going to want to be able to tell if a particular zone is getting water
flow through it.
3. After you've waited, turn the Tstat up on the 2nd floor zone.
4. See if you can hear/feel any flow through the 2nd floor zone.
(Probably not, if I understand the problem)
5. Turn the Tstat up on the 1st floor zone.
6. See if you can hear/feel any flow through the 1st floor zone.
(Probably yes, if I understand the problem).
7. Turn the Tstat up on the 3d floor zone.
8. See if you can hear/feel any flow throught the 3d floor zone.
(Probably yes, if I understand the problem).

If this is the case (1 & 3 get hot, 2 doesn't with all the Tstats calling for heat), then I'd definitely put money on the zone valve.
As long as the 2nd floor zone valve is working, it will get flow/heat if another zone is also calling for heat, regardless if that zone pump is working or not.

I'm assuming it is an electrically operated zone valve (based upon the 3 pump system).
It MIGHT be possible that it is a manual, thermostatically controlled valve (ie, you manually adjust a dial for the desired heat setting).
If this is the case, those valves have a rubber seat that will, after time, fall off and permanently plug the hole and prevent water flow.

If that is the case, you'll need to drain the system down, remove that zone valve, and replace it.


I don't think there is a problem with the pump.
Taco Pumps are good (cheap man's version of Bell & Gossett ).
Can one run hot while the other's run warm ? Yes, sometimes that's just the way it works.

bobman1235

All righty then. Lucky thing I decided to do one more once through the entire system before I went and replaced that pump. Over the summer there was a bathroom put in in the basement, and for some reason the plumber that did it decided to shut off a valve that happened to go through that room.... that valve being the one that goes to the 1st floor radiators. Open it up, h ear a rush of water, purge out some air, and we are IN BUSINESS.

Thanks to everyone for their help, sorry to send you all on a wild goose chase :-/

MillerLiteScott

Send the plumber a bill for your time.

disneyjoe7

Good too hear it was that easy.

mrbigbluelight

On my last post, I was bent over the keyboard with my butt crack showing.

:eek:

BaggedLancer

mrbigbluelight wrote: »

On my last post, I was bent over the keyboard with my butt crack showing.

:eek:

I leave my butt crack vented at all times....gotta keep the air flowing to prevent moisture build up.