Where did my hot shower go?

HotShowerPlease

Hello!

We have a Weil McLain GO4 tankless system.

Our hot water is no longer piping hot in the shower and tub and it comes and goes during the shower...about every 3-5 minutes there is a patch of cold for equal time. It seems to get much worse when the temp drops outside. We live on an island so it is hard to find someone knowledgeable about the system...so we are trying to trouble shoot!

We have had the system for about 12-13 years.

Thanks!!!

Erin

Gordy

Sounds like the tankless coil is scaled, and needs cleaned Erin. Is the heating working fine?

Is the domestic water pressure on the hot side the same as the cold, or is the hot side notably less?

HotShowerPlease

Hello!

The pressure on the hot side is way less than the cold. And yes the heating is working fine...forces hot water into radiators.

We have someone coming to clean it this week. Could that really affect it this much?

SWEI

It sure could. How hard is your water?

Gordy

Yes this would effect hot water production, and decrease water pressure on the hot side domestic due to the scale in the coil decreasing the piping diameter. It sound like the coil is scaled.

With the age of the boiler, and your water hardness do you condition the domestic water?

Do you know the hardness of your water?

Gordy

Be aware also that who ever is coming to clean the coil that acid cleaning will etch the piping surface making it rougher. This will lead to more frequent cleanings in the future due to scale being able to build more easily on the rougher piping surface.

It just depends on how fouled your coil is as to how aggressive the cleaning needs to be.

ChrisJ

There's also a chance, if it has one, that the mixing valve is bad as well.

Gordy

Yes that is also true if there is one. Erin do you have one? If so have the person cleaning the coil verify it is not fouled also.

HotShowerPlease

Thanks! Yes we have hard water but I'm not sure how hard. Is the mixing valve a difficult thing to check?

HotShowerPlease

Ok thank you guys!!! I will report back on Thursday if my showers are steamy again.

Robert O'Brien

Maintaining 500 lbs of cast iron and 15 gallons of boiler water at 180* 24/7/365 is a very inefficient way to produce DHW

ChrisJ

Robert O'Brien said:

Maintaining 500 lbs of cast iron and 15 gallons of boiler water at 180* 24/7/365 is a very inefficient way to produce DHW

Then why do so many on here recommend an indirect?
Basically the same principle no? Still have the boiler cooking away the entire time.

kcopp

ChrisJ said:

Robert O'Brien said:

Maintaining 500 lbs of cast iron and 15 gallons of boiler water at 180* 24/7/365 is a very inefficient way to produce DHW

Then why do so many on here recommend an indirect?
Basically the same principle no? Still have the boiler cooking away the entire time.

Key word... Maintaining. The tankless coil and the boiler has to stay hot 24/7/365.
An Indirect heats up and the boiler cools down. No flue, less stand by losses on an indirect.

Are there better boiler than others to do this sure.
That and I am not a fan of having a piece of heating equipment sitting idle all spring/ summer.

JUGHNE

A Mod Con would only cook water on demand from the indirect WH. And with dedicated controls ramp up to 180 to get the job done pretty fast.

STEVEusaPA

ChrisJ said:

Robert O'Brien said:

Maintaining 500 lbs of cast iron and 15 gallons of boiler water at 180* 24/7/365 is a very inefficient way to produce DHW

Then why do so many on here recommend an indirect?
Basically the same principle no? Still have the boiler cooking away the entire time.

I don't think it's the same principal. For one, the boiler doesn't maintain the 160-180 degree water temperature, and transitions more into a warm start boiler, only running when needed.
With more storage you get a longer run cycle to recharge the indirect, and usually never run out of hot water.
You also avoid short cycling as mentioned above, and the boiler doesn't fire practically every time someone turns on the hot water faucet.
I do agree they are in common use. Usually because they are being replaced with practically the same boiler, and people usually won't pay the added expense for an indirect and it's associated piping/components.
My boiler when not needed for heat, probably only drops down to about 110 degrees, and will fire about 3 10 minute cycles to recharge the indirect, for regular use and maybe one or 2 times more for washing clothes (multiple loads). I almost never hear the boiler fire for running the dishwasher.
In my case I think a .65 nozzle X 30 minutes a day (+-) is way cheaper than an electric water heater maintaining temperature, and cheaper and better for the boiler than a tankless firing multiple times per day for short cycles.
I almost never hear the boiler fire for running the dishwasher.

ChrisJ

Still a shame boiler manufactures can't do better than 1/2" fiberglass.

That's the main problem in my opinion. Throw 2" or 3" fiberglass on it and your losses will plummet. A damper kills most flue losses at least on atmospheric appliances.


The insulation is a problem whether you use the boiler for a tankless coil, an indirect or just for heat. I hate the amount of heat my boiler losses into the basement. This was most of the reason I dropped a tankless coil and did a stand alone power vented tank heater.

ChrisJ

JUGHNE said:

A Mod Con would only cook water on demand from the indirect WH. And with dedicated controls ramp up to 180 to get the job done pretty fast.

Sorry, I couldn't resist.

Gordy

I think Erin has a problem that she was looking for possible causes.

She lives remote. So oil, and or propane may be her only option.
13 years on a ci boiler is not long. As is 13 years on a tankless coil is not bad if this is her first issue.

An indirect would save her money in fuel if the budget allows, or as an option if the tankless coil ever goes down the tubes.

@ChrisJ your meme could not be farther from the truth. Mod/cons can make 190 water no problem. Sufficient for anything other than steam. Also you don't need a hand truck to bring it to the basement in pieces.........

HotShowerPlease

Ok so someone is here to "service" it now which I guess does not mean to descale the coil. He says he has only ever done that once in 12 years. He is almost refusing to do it saying it will take 5 hours and be super expensive and I should just get a tank. Is descaling really difficult? We replaced the could 3 years ago and it has never been touched since then.

ChrisJ

What is he going to do to it.
Look at it and pray? He came to service it, but he doesn't want to service it. I'm confused. Why is he there?


My understanding is you pour an acid solution into it, wait a bit and then flush it out.

HotShowerPlease

He says servicing it is just cleaning out the soot and whatever inside...not the coil. I said ok can u descale the coil and he said I was throwing good money after bad and should just get a tank. But he didn't look at the coil.

Did I mention I'm on an island? Not a lot of choice. Can a cute housewife descale it herself?

Gordy

Sooo this guy shows up cleans boiler, and still same performance?????

ChrisJ

HotShowerPlease said:

He says servicing it is just cleaning out the soot and whatever inside...not the coil. I said ok can u descale the coil and he said I was throwing good money after bad and should just get a tank. But he didn't look at the coil.



Did I mention I'm on an island? Not a lot of choice. Can a cute housewife descale it herself?

Sorry, I couldn't help but think of this.





Can you give us some pictures of the boiler, and the coil and piping around it? It's not too bad if it's plumbed correctly with service ports to connect hoses to.

ChrisJ

Gordy said:

Sooo this guy shows up cleans boiler, and still same performance?????

He allegedly cleaned the boiler, not the tankless coil.

Gordy

I know. Soooo my question remains.

Gordy

Nice schematic however if Erin does not have the service valves that makes thing a bit more difficult.

HotShowerPlease

He's still here cleaning the inside.

Gordy

Let us know if he cleans coil. Sounds like he is trying to sell the indirect.

Abracadabra

HotShowerPlease said:

He's still here cleaning the inside.

He needs to descale or you're not getting anywhere..
if it were me i'd send him packing

He's just going to clean the boiler/soot/etc then he'll show you that you still have the same problem.. then tell you to buy a new one

ChrisJ

Gordy said:

Nice schematic however if Erin does not have the service valves that makes thing a bit more difficult.

Ahem,

"Can you give us some pictures of the boiler, and the coil and piping around it? It's not too bad if it's plumbed correctly with service ports to connect hoses to."

HotShowerPlease

It was the mixing valve...which was the other thing you guys said to check. Water was 180 coming out of the coil but only 100 going up the pipe. 15 minute fix and I have pressure and amazing hot water. Thank you sooooo much. Walter wouldn't have checked it if I wasn't pushing with your information. Merry Xmas!!!

Gordy

Welcome merry xmas