zoned hot water system problem
RayV
Boiler in basement
Split level house with all zone loops higher than basement
Three zones - all thermostats working properly
Circulator pump on the cold/return side of boiler mounted just above
boiler inlet
comes on with furnace (zone independent)
Flo-control valve on the hot/supply side of boiler mounted near ceiling
Air separater right after main flo-control valve with bladder expansion
tank
Three additional zone circulator pumps connected to the thermostat
relays
Three zone flo-control valves, one right after each zone pump
The problem is that whenever any zone calls for heat there is flow thru
all three zones. I verified that each of the zone pumps are working
independently and correctly. He told me that the system has always
operated this way and he just sets the thermostat on the upper level to
50 so it never kicks on because he always gets heat up there.
There are no zone valves on any of the zones, only the flo-control
valves. The zone pumps, flo-control valves and thermostats appear to
be add-ons to the original system.
I would like to hear ideas on possible repairs or system changes that
would get the system to only heat the zone(s) that is calling for heat.
.p.jm@see_my_sig_for_address.com
Find out what is letting hot water flow through non-calling
zones.
Fix it.
Any moe detailed advice than that requires someone who knows
what they're doing to be there and examine the system.
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dd
"RayV" <Nunya...@comcast.net> wrote in message
news:1162407528.5...@k70g2000cwa.googlegroups.com...
> My BIL has a problem with his system, here's the current setup:
> Boiler in basement
>
> Split level house with all zone loops higher than basement
>
> Three zones - all thermostats working properly
>
> Circulator pump on the cold/return side of boiler mounted just above
> boiler inlet
> comes on with furnace (zone independent)
>
> Flo-control valve on the hot/supply side of boiler mounted near ceiling
>
> Air separater right after main flo-control valve with bladder expansion
> tank
>
> Three additional zone circulator pumps connected to the thermostat
> relays
>
> Three zone flo-control valves, one right after each zone pump
>
> The problem is that whenever any zone calls for heat there is flow thru
> all three zones. I verified that each of the zone pumps are working
away
RayV
Steve Scott wrote:
> Flow checks are open or failed if the pumps are operating properly.
I cranked the flo-controls to the full open position and ran all of the
pumps to flush out any sediment that might be on the seats then closed
them. I did just change one of the zone pumps for him and the
flo-control for that zone held the water in the pipes while I changed
the pump.
>
> Is the supply and return manifold piped completely separate or are
> they connected at some point other than through the loops?
The supply pipes are teed right after the air separator and the returns
don't come back together until right before they go to the inlet
circulator pump.
>
> What is used for heat emitters? Baseboard?
Yes, standard baseboard around the perimeter of each level.
RayV
> > all three zones. I verified that each of the zone pumps are working
> >
> Shut off the circulator mounted at the boiler return bet the problem will go
> away
Doesn't having the pump(s) only on the outlet side of the boiler
increase the chance of a boiler overtemp?
I suppose I could just disconnect it and run each zone for 20 minutes
and see what happens.
RayV
Steve Scott wrote:
> Generally speaking, a typical residential system that's properly piped
> and is in a standard series loop configuration w/o primary/secondary
> piping will only have circs on the supply side after the expansion
> tank.
>
> What makes you think not having a return circ would cause excessive
> boiler temp?
>
This is the third house I've seen in this area (Eastern PA and NJ) with
a pump on the return side of the boiler. One was a ranch with no
zoning, the other had one pump with three zones with zone valves after
the boiler (worked fine), and this crazy system with four pumps!
Of course most of the houses in this area have the shingles overhanging
the sheathing by 1.5" so they hang in the gutter but that isn't right.
RayV
Steve Scott wrote:
> The purpose of the flow check isn't to hold the water when you pull
> the valve, it's to keep other circs from moving water through a loop
> that isn't calling.
>
> That said, if the system worked properly at some point in the past,
> loops are heating up now when that circ isn't firing then either the
> flow checks are open or they're not working.
>
The system hasn't worked properly in the 8 years since he has been
there. It may have never worked properly.
Could have been the previous owner had it 'zoned' because it was colder
in some parts and was sold all these extra circulator pumps and relays
when all he needed were a few zone valves.
DIMwit
flange mounted on a chrome pipe from the boilers return port, bottom left
corner. This one shows the circulator(s) or zone valves in the outlet port.
My own boiler (P-468) is using the return port. I use one motor and 5! zone
valves. One is the Super store tank circuit.Works super.
http://www.weil-mclain.com/FTP/GOLD_Oil_Manuals/Wgoboilermanual.pdf
Bob
"RayV" <Nunya...@comcast.net> wrote in message
news:1162466333.1...@k70g2000cwa.googlegroups.com...
dd
probably 90% are done this way, I have also done systems with the circs on
the supply as pushers and I really don't think it make a difference,
although I don't think as pushers you will have problems because of air in
the piping.
"Steve Scott" <ssc...@twcny.rr.com> wrote in message
news:6rljk2dg1r3eq4268...@4ax.com...
> Manufacturers have for years installed circs on the return side which
> is wrong. They should be on the supply side after the expansion tank.
>
> Pumps on the supply side and return side usually indicates some sort
> of half assed attempt at primary/secondary piping. You might use them
> if you had a heluva pressure drop through the system.
>
> On 2 Nov 2006 03:15:04 -0800, "RayV" <Nunya...@comcast.net> wrote:
>
AKS
you have 4 pumps running in parallel on return side
without zoning valves or check valves on supply
side (discharge) but just the flow valves
no wonder you customer is having problem
PUT CHECK VALVE ON EACH PUMP DISCHARGE
you problem will be eliminated
Dido say that
"RayV" <Nunya...@comcast.net> wrote in message
news:1162407528.5...@k70g2000cwa.googlegroups.com...
RayV
Steve Scott wrote:
> Where are the fill valves located on the systems you see?
At the same level as the boiler inlet or lower.
>
> You're right about less air problems with the circ on the supply side.
> Do you know why that is?
Higher pressure from the hotter water raising the boiling point?
>
> Where should the fill valve be?
Close to the boiler inlet.
> Why?
Because it is easier to run the piping?
RayV
AKS wrote:
> If I understanding you right
> you have 4 pumps running in parallel on return side
> without zoning valves or check valves on supply
> side (discharge) but just the flow valves
> no wonder you customer is having problem
> PUT CHECK VALVE ON EACH PUMP DISCHARGE
> you problem will be eliminated
> Dido say that
>
One pump on the return side at boiler inlet
Three pumps parallel on the outlet side after air separator/expansion
tank
Three flo-control valves after each pump on the outlet side
No zone valves but the flo-control valves are also check valves
http://www.bellgossett.com/Press/BG-flocontrol.asp
How would a 'check valve' on each pump discharge solve what seems to be
an unneeded pump on the inlet side that is pushing hard enough to lift
the flo-control valves in the two zones not calling?
RayV
Steve Scott wrote:
> On 2 Nov 2006 18:23:13 -0800, "RayV" <Nunya...@comcast.net> wrote:
>
> >
> >Steve Scott wrote:
> >> Where are the fill valves located on the systems you see?
> >
> >At the same level as the boiler inlet or lower.
>
> Is the fill valve before the circ? Replace many expansion tanks?
>
> >> You're right about less air problems with the circ on the supply side.
> >> Do you know why that is?
> >
> >Higher pressure from the hotter water raising the boiling point?
>
> The circ causes pressure differential. So, the expansion tank is the
> point of no pressure change and the suction side of the circ is close
> to the tank the circ adds to the static system pressure. That causes
> the pressure to be as high as possible at the highest point in the
> system.
>
> If the circ is on the return side and the expansion tank is on the
> supply side the highest points of the loops can be under negative
> pressure causing air to migrate into the water...even from water tight
> solder joints.
>
> >> Where should the fill valve be?
> >
> >Close to the boiler inlet.
> >
> >> Why?
> >
> >Because it is easier to run the piping?
>
> point of no pressure change.
>
> What we all commonly see is the expansion tank of the supply side, the
> circ on the return side (cause the boiler manufacturer stuck it there)
> and the fill on the suction side of the circ. This is a guaranteed
> revenue stream as you will be replacing the expansion tanks regularly
> and maybe the relief and fill valves trying to figure out what the
> heck is going on.
>
> The problem is this:
> Fill valve and tank factory set at 12psi. Who changes them?
> Virtually no one.
>
> So the circ is off and the system is full there's 12psi at the fill
> and at the expansion tank.
>
> Let's assume the circ creates 6psi differential. The expansion tank
> is the point of no pressure change so that stays at 12psi. There's
> maybe 1psi loss through the boiler so the outlet side of the circ is
> at 13psi (12psi at the tank + 1psi through the boiler). The circ
> creates 6 psi differential so the suction side is 7psi. Which is what
> the fill valve is seeing cause it's on the suction side of the circ.
>
> Wait a minute. The fill valve is set at 12psi and now it's seeing
> 7psi? What's it gonna do?
>
> Add water?
>
> Yep.
>
> Where's the water go?
>
> The only place it can go is the expansion tank. The rest of the
> system is already full.
>
> What happens when the expansion tank has too much water in it?
>
> The diaphragm ruptures.
>
> And that's the short version of why in a correctly piped system the
> expansion tank goes in the supply near the boiler with the feed near
> the expansion tank and the circ right after the tank. With very few
> exceptions.
>
Thanks for the explanation. Easy to understand and makes perfect sense
the way you explained it. A welcome difference from the way most posts
are written.
I'm going to disconnect the pump on the return side of his system and
run the zones to see if that cures the problem of non-calling zones
always getting hot.
Thanks again.
AKS
>
> AKS wrote:
>> If I understanding you right
>> you have 4 pumps running in parallel on return side
>> without zoning valves or check valves on supply
>> side (discharge) but just the flow valves
>> no wonder you customer is having problem
>> PUT CHECK VALVE ON EACH PUMP DISCHARGE
>> you problem will be eliminated
>> Dido say that
>>
>
> One pump on the return side at boiler inlet
>
> Three pumps parallel on the outlet side after air separator/expansion
> tank
>
> Three flo-control valves after each pump on the outlet side
>
> No zone valves but the flo-control valves are also check valves
I see what are you saying
check and examain valves see that valve is doing
what it it should be doing
Dido
Stormin Mormon
there, less damaging to the check valve.
--
Christopher A. Young
You can't shout down a troll.
You have to starve them.
.