Lukewarm and insufficient hot water in mild weather

LynnLennox

I read a similar problem posted by user Wedgemoose in Mostly Steam. I have a Smith steam boiler and a Burnham hot water tank. The boiler is about 11 years old. The tank was replaced Dec. 2014 when the old one sprang a leak. The problem I have goes back several years, and is common to the current and previous tanks. I have mentioned this problem to every technician that comes to service my boiler each fall. They all look at me like I have lobsters coming out of my ears. I live in Maine (so maybe I do). During the winter, when the boiler is running a lot, we have plenty of too-hot water. You could scald yourself but since right now, there are no little ones using the faucets, it's OK. We know to be careful. As soon as the weather starts to get mild, and the boiler is running infrequently or not at all, the water temperature is barely hot and plentiful enough for one shower. The second person to shower gets tepid water that runs out even during a quick shower. In addition, the shower control is off at 6 o'clock, hottest setting at 12 o'clock. In the winter, you'l put it at about 8 or 9 o'clock max. This time of year (early June) putting the handle at 12 o'clock is not quite hot enough. This morning I took photos of various components. They are in order of appearance: (1) Current setting on tank (about 120 -- I must remove the foil tag to set it higher) (2) Dial on side of Aquastat set to 5 -- is this the differential? (3) Tank brand (4) Boiler make and model (5) Aquastat currently set to 160 (6) Control on tank - Diff at 5 (7) Aquastat label inside cover.

This problem is ongoing during mild and hot weather. Hot water after one shower is hit or miss during the day and we never know if it's a good time to run the dishwasher, for example. Can someone suggest what settings I can try to resolve this issue? Thank you in advance!

LynnLennox

Thank you so much for your quick reply! I will try this today and let you know how it goes.

LynnLennox

I wanted to gather a couple of days' worth of info before responding again. I made the recommended changes Sunday evening. Monday morning my husband showered first. He mentioned that he did not have to turn the shower handle completely to 12 o'clock to have comfortable water temperature. We have family visiting this week and our 5 year old grandson took a short shower. My daughter-in-law took a long shower and started to run out of hot water near the end. (about a 15-20 minute shower). 2 hours later, I reluctantly showered with no hot water. It was barely tepic. Tuesday, I showered for about 4 minutes. My daughter-in-law took a Navy shower -- maybe 6-7 minutes total. My husband showered for about 5 minutes and did not run out of hot water. So, a few questions:

The differential on the tank is still at 5. Is that OK or should I have changed that to 20 as well?

I was confused that after the hot water was depleted on Monday morning, I did not hear the boiler running at all. Shouldn't it have kicked in right away?

How long should this type of system take to recover?

Thanks for all your help and let me know if you need more information from my end.

LynnLennox

OK. I'll need some help on this. There is a Taco Cartridge Circulator attached to the tank. Is this the pump? If not, what am I looking for?

How do I know that the aquastat on the tank has "closed?"

Thanks again for all your prompt replies and help!

Robert O'Brien

I'd be surprised if it weren't the indirect aquasmart. Been there and done that

LynnLennox

I was awake early and heard the boiler kick in from 4:54am to 4:58. I fell back to sleep. I got up after 8 and noted that the boiler ran again at 8:45am for a few minutes. No one else in the household was up and there had been no demand for hot water. At 9:02 I went to the basement while my husband started his shower. I noticed the pump was already vibrating. The copper tubing was pretty warm -- too warm to comfortably grab the pipe and hold it. The boiler was not running and was not hot to the touch. The light on the tank's aquastat is blinking green. About 2 minutes after his shower, the boiler kicked in for just a couple of minutes. As a side note, I hear the pump a lot (I didn't know what it was before this.) I have extremely sensitive hearing and can often hear the pump (makes a kind of ticking sound) from the upstairs bathroom, which is pretty much a straight shot up from the boiler in the basement. So unfortunately this didn't go as planned, i.e. the pump was already running without any hot water demand all night. Does any of this help in figuring out what's going on? Thanks again.

LynnLennox

You are correct, I just touched the outside. What is the boiler block?

In the winter, my glass is always about at the half way point. If I remember correctly there is a water level line on the boiler itself, next to the glass tube. I do have an automatic feed to the boiler. I typically don't add water. I do flush the low-water cut-off valve pretty often (with the boiler running), especially in the winter and use that opportunity to hang around and see if the auto-feed functions correctly (twice I've had the auto-feed malfunction and over fill the boiler so I don't trust them.) I can take a photograph of the glass and that line. Would you rather the boiler be running or not when I do that?

In addition, in 2009 we had a renovation of the back half of our downstairs. One radiator was added and others were moved around. There were numerous issues when heating season started and the plumber had to redo some of the piping to the radiators. I had ongoing issues with water hammer and lukewarm radiators. I ended up buying Dan Holohan's book on steam heat to understand things more. In particular, I wondered if our near-boiler piping was correct. I spoke with a plumber about it and he said it needed to be re-piped. I have the plumber's description of what he did on the invoice if you are interested in what he wrote. I mention it because it involved the lowering of the low-water cutoff. I apologize if I'm offering too much info but I figure better too much than too little. Thanks again.

LynnLennox

Good morning, Sorry for the delay in response. Family guests have left and I can get back to this now. This morning here's what I found. The boiler block (I touched the only exposed part I could see, i.e. where the burner is connected) was warm. The pipes to the tank were hot. The pump was not running; the boiler was not running. I have taken photographs of the water levels. My auto-feed does have an over-ride button so I filled it to a bit above the maximum level for steam.




The photos are (1) the glass as I found it this morning, (2) the glass and the level indicators on the boiler, (3) closeup of the level indicators, and (4) the water level after adding water. In the last photo, the water in the tube caught the glare of the flash so the white you see is the water. I have noted that the normal level I usually see in the glass is at the minimum level. I know it bounces up a bit when the boiler is running. We'll see how the hot water goes this morning with showers and doing dishes and I'll report back. Thanks again.

LynnLennox

More follow up: The last 3 days (with only 2 of us in the house) hot water has been more than hot enough and plentiful for showers, dishes, hot water laundry loads. So does that mean adding water to the boiler helped? Am I being too dependent on the auto-feed (which seems to just keep the level at minimum)? We'll have more house guests as the summer goes on so a real test will be to see what happens when 4 adults are showering each day.

LynnLennox

Thank you. I had no idea. I will check that out next trip to the basement. What would be the reason if the auto-feed is not giving the boiler sufficient water? Is the feed really more of a safety-catch than a mechanism to keep the boiler's water level at an optimum level?

LynnLennox

Thanks again for all your help and fast replies. I'm very grateful for this resource. We need more people like you in this field. I'm afraid many just don't fully understand or even basically understand these issues. I asked a couple of different guys about the aquastat and they just looked at me like they resented the fact that I even knew what that was! I'll post again when we have more family visitors this summer and let you know how it's doing with more demands for hot water than usual.