My 40 gallon natural gas hot water heater is not keeping up anymore.?

by Water Heaters on August 31, 2010

There is a large flame and everything had been working well, but lately we can only get in one hot shower.
Shower head is new in one bathroom, but water is cold in every faucet. I turned it up, and within 4 hours the water is very hot, but still doesn’t last long. It is insulated, but we do live in Minnesota and it is just now getting very cold outside. Thanks to everyone for your answers.


Other Articles and Posts

Read Related Posts

    No related posts found

{ 10 comments… read them below or add one }

T C August 31, 2010 at 9:56 am

Have you changed shower heads lately?

If everything else is functioning properly you may have a build up of sediment. Draining it may help some but if it is that severe …..draining it may be an exercise in futility.

Also if you are in a colder region …ground water is much colder this time of year ….meaning recovery time on a water heater is going to be slower ………….Just adjust the temperature

mich August 31, 2010 at 9:56 am

Have you tried getting it inspected?

Have you wrapped it in insulation?

RobT August 31, 2010 at 9:56 am

at the bottom of the tank is a dial… look at it and turn the dial slightly clockwise just a little bit.

this should make the water hotter ( but it will cost a little more to keep it heated to that temperature).

liesse61 August 31, 2010 at 9:56 am

Could be one of a few reasons. Lime build up. Partly blocked pipes that need to be replaced. Or the bottom of your pick up tube has deterioated. Lime build up in the tank means new water heater, partly blocked pipes means repiping home. I would start with a simple pick up tube replacment. They can be purchased at your local home improvement store.

Robert F August 31, 2010 at 9:56 am

Did it start this suddenly ? or over a period of time ,like a year or two ?

There should be a boiler drain at the bottom , try hooking a hose to it and run it to the tub drain and let it run until clean water flows . If stopped up tou will have a mess if you take the drain apart to open it up do drain . these need to be flushed every so often , here we usually recommend yearly to keep the sediment under control. and allowing the water to heat more quickly at the bottom without the added material
The fill tub could be broken and allowing the cold water in at the top and mixing with the hot , thus cooling the hot water very quickly

R J August 31, 2010 at 9:56 am

Time for a new one. There is too much crud in the bottom of the water heater for it to work properly. You are just wasting money to heat a little bit of water. You can try to drain it but if it is more than 5 years old, it is time to replace it. On the next one you purchase, drain it every 6 months to a year and that will keep it clean so that it will last long past the rated period.

Steve G August 31, 2010 at 9:56 am

How old is it? If from the mid-90s, see this link:

http://www.diptube.info/

…then start shopping for a new water heater.

Corky R August 31, 2010 at 9:56 am

R J is correct here. You really need a new unit. Most likely your old heater is about half full of lime, calcium buildup. That means that your standard 40 gal. heater is now down to probably about 20 gal. or less, which won’t give you a very long hot shower. The lime and calcium content in some areas is horribly high and when it gets heated while it sets in the tank, it just precipitates out constantly. So over the years it just builds and builds and builds. Draining with the standard draincock factory installed on water heaters is actually quite useless, for trying to get rid of chunks of calcium that are probably the size of your thumb or larger. They just won’t go through the opening. I’ve removed many of these units and frequently we have to siphon the water out the top through one of the water inlet pipes because there’s so much lime in the bottom the water can’t get out of the spigot any more, and they weigh a ton. Calcium and lime accumulation is really heavy. From what you’re telling us, I’d say that when you do replace this unit, you should seriously consider either installing a water conditoning system for the house, or get a really good self cleaning water heater.

Mr Fixit August 31, 2010 at 9:56 am

should heat up in less than 10 minutes. However it is only 40 gals…about enough for one shower.
Remember as you remove hot water from the tank cold water goes in.

listurhopes August 31, 2010 at 9:56 am

12 to 15 minute shower with 7-10 gallons per minute with no water saving device. 2-4 gallons per minute with a water saveing device.

4 gals x 12 minutes = 44 gallons so one shower per tank.

see link.

Leave a Comment

Previous post:

Next post: