Posted by aparnaphadnis on June 4, 2007, 7:59 am
Hi all,
We just moved into a 1968 yr built house in the North east.
It has an oil fired furnace, which supplies the hot water to the
bathrooms etc as well as circulates the hot water for the baseboard
heat.
In the past we have always lived in houses with electric heat and
water heater, so this is all new.
We have three heating zones and as far as we know, the house stays
pretty warm.
As far as the faucets in the bathrooms, kitchen, dishwasher etc. there
is a good supply of hot water.
However, the hot water runs out in the showers within the first five
minutes. We have had 3 plumbers look at the problem so far and none of
them are able to resolve the problem.
We put in a new mixing valve at the boiler, this made it a little
better than before when we were getting hot water only for a couple of
minutes.
What is puzzling is that it is happening only at the showers. It is
also happening at all the 3 showers in the 3 bathrooms.
The 3 plumbers each had a different solution for the problem (each on
just as expensive):
1. Boil the coil to remove any deposits/scaling.
2. Connect a 50 gal Electric water heater.
3. Connect a hot water booster to boost the heat.
My questions for each solution are:
1. How come there is scalding hot water in the faucets? Does that not
indicate that the coil is fine? Moreover, if I touch the piping at the
boiler, it is very hot.Why only the showers?
2. What will happen if I do connect an electric water heater? Will it
start up everytime I am turning on the room heat too? If that is the
case, I would be incurring a huge electricity bill for something that
is working fine (baseboard heat).
3. For the hot water booster too, if it is based on electricity, I am
asking for a big bill every month.
My question is why is this happening ony at the showers?
One plumber suggested it may be due to the single valve at the shower
that adjusts the hot/cold. But in another bathroom in the house, I
have two seperate valves for the hot and cold water and I still run
out of hot water in there within 5 minutes.
If anyone has any experience with this kind of problem, please help
because its bearable now but will not be during the cold days of
winter!!
Thanks in advance.
Posted by Ecnerwal on June 4, 2007, 8:47 am
aparnaphadnis@hotmail.com wrote:
> 1. How come there is scalding hot water in the faucets? Does that not
> indicate that the coil is fine? Moreover, if I touch the piping at the
> boiler, it is very hot.Why only the showers?
This is very typical of a scaled (mineral-deposited) hot water coil.
Plumber 2 gets a zero. Plumber 3 might or might not get a zero,
depending what is meant. You might try calling the oil burner service
folks in for a 4th estimate - as a new oil furnace owner, know that an
annual service visit by a licensed service technician is both a good
idea, and commonly a requirement to have your oil delivered. They know
all about furnace hot-water coils, as well as proper adjustment and
cleaning of the burner.
Put a bucket under the shower head. Run it until it gets cold, measure
both time and volume.
Now run the same amount of water from the faucet. Measure the time, and
observe the temperature. I seriously doubt that you are typically
running the same volume over time of water in the "scalding hot sinks"
as you are in the "showers that get cold". If the facets run much slower
(less water volume per time) the boiler may keep up better. If you
simply never run 15 gallons from the faucet, you're never going to get
to the water use typical of a shower (and that's assuming a 3GPM
low-flow showerhead - you may be using much more).
Potential solutions that make any sense (other than shorter showers, and
low-flow showerheads if you don't have those in place ) - if the sinks
really are scalding, adjust that new mixing valve correctly. Descaling
(or simply replacing - cost is often similar) the hot-water coil in an
oil boiler is a typical maintenance item. Future need to do this ("the
next time") can be strongly affected by spending yet more money on a
water softener, at least for the hot water feed water. A properly
working coil system should provide "near infinite" hot water, as the
furnace runs to provide heat as the water it drawn through the coil. The
coil system is the most compact arrangement (not tank) and simplest (no
pump).
The option which is not on the menu (unless 3 is a poorly worded attempt
at describing it) that holds up a bit better to scale (but typically
costs yet more) is a "hot water maker" - a tank with its own heat
exchanger, separate from the boiler, completely replacing the coil,
which holds a volume of water and runs heated boiler water though an
exchanger internal to the tank. It goes onto the furnace as a separate
"zone" with its own pump. For various reasons, primarily the larger
passageways and the fact that the inside of the exchanger coil on this
type is only exposed to recirculating boiler water, these "scale up"
much less than a coil. They will still benefit (in the long run) from a
water softener if your water is prone to scaling up the present coil in
the furnace.
--
Cats, coffee, chocolate...vices to live by
Posted by Gordon Richmond on June 4, 2007, 11:10 am
>Hi all,
>We just moved into a 1968 yr built house in the North east.
>It has an oil fired furnace, which supplies the hot water to the
>bathrooms etc as well as circulates the hot water for the baseboard
>heat.
>In the past we have always lived in houses with electric heat and
>water heater, so this is all new.
>We have three heating zones and as far as we know, the house stays
>pretty warm.
>As far as the faucets in the bathrooms, kitchen, dishwasher etc. there
>is a good supply of hot water.
>However, the hot water runs out in the showers within the first five
>minutes. We have had 3 plumbers look at the problem so far and none of
>them are able to resolve the problem.
>We put in a new mixing valve at the boiler, this made it a little
>better than before when we were getting hot water only for a couple of
>minutes.
>What is puzzling is that it is happening only at the showers. It is
>also happening at all the 3 showers in the 3 bathrooms.
>The 3 plumbers each had a different solution for the problem (each on
>just as expensive):
>1. Boil the coil to remove any deposits/scaling.
>2. Connect a 50 gal Electric water heater.
>3. Connect a hot water booster to boost the heat.
>My questions for each solution are:
>1. How come there is scalding hot water in the faucets? Does that not
>indicate that the coil is fine? Moreover, if I touch the piping at the
>boiler, it is very hot.Why only the showers?
>2. What will happen if I do connect an electric water heater? Will it
>start up everytime I am turning on the room heat too? If that is the
>case, I would be incurring a huge electricity bill for something that
>is working fine (baseboard heat).
>3. For the hot water booster too, if it is based on electricity, I am
>asking for a big bill every month.
>My question is why is this happening ony at the showers?
>One plumber suggested it may be due to the single valve at the shower
>that adjusts the hot/cold. But in another bathroom in the house, I
>have two seperate valves for the hot and cold water and I still run
>out of hot water in there within 5 minutes.
>If anyone has any experience with this kind of problem, please help
>because its bearable now but will not be during the cold days of
>winter!!
>Thanks in advance.
It's not clear to me exactly how your furnace heats the water supply, but when
this
problem occurs in free-standing tank-type water heaters, it is often caused by a
broken
"dip tube". The water inlet and outlet are both right on top of the tank, but
within the
inlet nipple is an internal plastic sleeve that conducts the cold water down to
the lower
part of the tank, so that as hot water is drawn off the top, the cold comes in
near the
bottom to replace it. If the dip tube is broken, once a little hot water is
drawn off, the
incoming cold water simply circulates across the top of the standing water in
the tank,
and your outlet water runs cold.
I have had this happen. It is a cheap and easy fix, though. One simply removes
the fitting
from the cold water inlet, fishes out the flange from the busted dip tube, and
drops in a
replacement dip tube, and reinstalls the fitting. The broken dip tube can be
allowed to
remain in the tank. I have done this repair myself at least twice.
Whether the above applies in your situation, I can't say for sure.
Gordon Richmond
Posted by Gordon on June 4, 2007, 9:25 pm
david.williams@bayman.org (David Williams) wrote in
> -> As far as the faucets in the bathrooms, kitchen, dishwasher etc.
> there -> is a good supply of hot water.
> -> However, the hot water runs out in the showers within the first
> five -> minutes. We have had 3 plumbers look at the problem so far and
> none of -> them are able to resolve the problem.
> -> We put in a new mixing valve at the boiler, this made it a little
> -> better than before when we were getting hot water only for a couple
> of -> minutes.
> -> What is puzzling is that it is happening only at the showers. It is
> -> also happening at all the 3 showers in the 3 bathrooms.
>
> You imply that you have hot water at the faucets at the same time as
> there is no hot water in the showers. Right?
>
> The only explanation I can think of is that the hot water to the
> showers leaves the tank from a different, and lower, outlet pipe than
> the water to the faucets. So when you run the showers, cold water goes
> into the bottom of the tank, and soon gets up to the level where the
> outlet to the showers is. So the showers go cold, even though there's
> still plenty of hot water in the upper part of the tank.
>
> But why would anyone rig up things that way, unless he was trying to
> discourage people from taking long showers?
>
> dow
>
No, It's because there is still hot water in the pipes going to the
faucet. If the faucet was run long enough it too would run out
of hot water.
Usually the problem with a shower running out of hot water is due
to the lower element of the hot water heater being burnt out. Only
the top element is working and is heating the top of the tank. the
rest of the tank is full of cold water. It doesn't take long for a
shower to exhust the limited supply of hot water.
It could also be due to the dip tube failing. This was a problem
a few yeas ago.
Posted by Ecnerwal on June 4, 2007, 9:48 pm
> Usually the problem with a shower running out of hot water is due
> to the lower element of the hot water heater being burnt out. Only
> the top element is working and is heating the top of the tank. the
> rest of the tank is full of cold water. It doesn't take long for a
> shower to exhust the limited supply of hot water.
>
> It could also be due to the dip tube failing. This was a problem
> a few yeas ago.
Neither of which has anything to do with a oil-fired-boiler with
hot-water coil system such as the original poster has. No tank, no dip
tube, no element.
--
Cats, coffee, chocolate...vices to live by
XML site map
> indicate that the coil is fine? Moreover, if I touch the piping at the
> boiler, it is very hot.Why only the showers?