Weil McLain Ultra 105 Temp Rise Too Quickly Error

StevenP

Hello,
I am looking for some help in determining the root cause for an auto reset error (temp rise too quickly) I am having with my boiler. I have noticed this errors occurring for the past month or so. I've had an HVAC company (picked from the Weil McLain website list) come out a couple of times and try the following items to fix it.
1. Purge the air from the system (both the first floor zone and the second floor zone)
2. Confirm the main boiler pump (the black Taco 007) has voltage and measure the current of ~0.70A
3. Measure the resistance of the Supply temp sensor
a. It was out of spec and I recently replaced both the return and supply sensor, but it didn't fix the issue
4. Confirm / adjust the natural gas pressure being supplied to the boiler (from the regulator to the boiler)

I have attached pictures of the installation to the post. The boiler was installed in November of 2011 (I was not the owner that this time and have bee in the house of 1.5 years). When I have been standing in front of the boiler and the error has occurred I have noticed the following;
1. Most of time (all of the times I have seen it happen except for once) has been when zone 3 (second floor heat) is calling for heat and is the only zone calling for heat. Meaning only zone 3 calling for heat and not zone 2 and 3.
a. Also note, the one time I saw this happen with zone 2 it was also the only zone calling for heat (not zone 2 and zone3)
2. The error occurs within ~10 seconds after flame has started in the boiler.
a. The boiler goes through the pre-purge time, ignition, flame and then soon after flame the error occurs
3. Once the error occurs the screen turns red and the boiler goes through the auto reset process (the pumps are all running at this time). After the reset process finishes it goes back through its normal start up process and works without an issue.
4. I have also attached an Excel file and PDF file that both show the Lock Out history information for the boiler. I have two sets of information. One is from errors I got with the old temp sensors and one is for the errors I've gotten with the new temp sensors.

Please note the error information shows the return temps as higher than the supply temps. However, I dont believe the sensor wiring is swapped between the two because when its running the supply temp is ~20F higher than the return. Additionally, the first floor of my house is ~1071 sq ft and the second floor is ~1000 sq ft.
Can anyone take a look at this information and let me know your advice? Thank you and please let me know if you have any questions. Thanks again.

DZoro

Not a big fan of the piping layout. What is your system pressure? Where the boiler pump is wired to the main boiler, go in and confirm good positive connections there and at the pump. When this happens again would be nice to check for 120volts to the pump. Also at that time you should be able to hear the water flow by closing down the valve opposite of the pump.

Is the supply pipe 1"? Both returns also 1"? Are the check valves still in the pumps? Do you ever hear air in the rads. or the system?

StevenP

Dennis,
Thanks for the feedback. Using the analog gauge on the front of the boiler the system pressure is a little below 20 psi. I can check the voltage next time it happens, but the last time it happened I put my ear next to the main boiler pump and could hear it running (for what it’s worth). Are you suggesting closing the main valve on the return side (right above the boiler pump)? Won’t that make the problem worse?
The supply pipe looks to be 1.25” and the returns appear to be 7/8”. The first floor zone(zone 2) appears to have two returns pipes going to pump and second floor zone (zone 3) has one pipe. I don’t know if both check valves are in the pumps for zones 2 and 3. Is there a way to check without removing the pumps? I don’t think I hear air in the hot water baseboards. I think what I hear is normal expansion sounds. Thanks again.

Zman

I would agree that an intermittent circ is the most likely cause. The return temp is higher than the supply when it errors.
You could swap it with the other 007.

Zman

BTW, If there was an award for most thorough and complete post, this would get my vote. Nice Work!

StevenP

Can the 007 taco pump used on the boiler be replaced with a 007e taco pump?

StevenP

Thanks for the comment Zman

hot_rod

I think the is a bypass valve inside that boiler, make sure it is in the correct position. One way is for primary secondary piping, the other for direct piping.

Also make sure the boiler pump is installed flowing the correct direction.

Zman

StevenP said:

Can the 007 taco pump used on the boiler be replaced with a 007e taco pump?

Yes

DZoro

What I meant to say is that when the black system pump is supposed to be running but your in the fault mode. Just throttle the valve down and listen for water flow pushing through the valve while your opening and throttling down that valve. Don't ever want to fully close it. Always return it back to fully open position. This is a technicians way of testing actual flow through a pipe. It is used to just confirm pump is on and there is some flow or none.
@hot rod yes confirm that position if it has the bypass.
I think on that one those blanked off tees are to be used for the domestic.

HVACNUT

Adjust the post purge for a longer run time.

kcopp

Is it possible that because the circulators are on the return and the expansion tank <24" away on the supply that that is causing a flow issue?

StevenP

HVACNUT. The postpump time is currently set at 90 seconds and the prepump time is currently set at 35 seconds. I was thinking about increasing the prepump time to get the return water temperature at more of a steady state since the error occurs so soon after the flame starts (its not really heating up the water much at this point in the process). I was wondering if the error is happening because 'hot' water is flowing from return, into the boiler, and then making the supply sensor see a fast increase in temperature causing the error. Of course this all assumes I have good circulation in the first place and don't have a problem with the main boiler pump.

StevenP

@Hotrod can you please explain the difference between primary secondary piping, the other for direct piping? I am not sure which setup I have. Thanks.

DZoro

Piping arrangement is not the best. You do have primary/secondary. But all the pumps are pumping into the pressure tank, ( should be pumping away) and then reduced to a single 1" supply. That should have stayed at least 1 1/4" . No easy way to correct those issues without doing a major re pipe. You had the place for 1 1/2 years, has it ever worked properly? I would try increasing the pre pump longer. But 35 seconds should have been enough pump time to get proper flow through the boiler.

StevenP

Dennis, I think the supply is 1 1/4 “. I am not sure if it’s been having this issue the entire time I’ve owned the house or not. Would a prepump time change from 35 to 60 seconds be a good start?

DZoro

Could be but looks like the supply comes into the spirovent 1 1/4 and out 1" . Have you been able to confirm the pump operating and pumping during a failure?

StevenP

Dennis you are correct about the pipe sizing. I haven’t seen it happen again....yet

ChrisAK

What was your solution?

Norm28

Weil McLain Ultra...Check Your Target Temp. On Ultra Screen it may be set at 190 deg with Boiler max setting at 200 deg. you could lower to 180 deg. Because the Boiler does overshoot the set Temp. By a few degrees. Also the circulator may give a good amp reading even though the Impeller on the circ. Could be wiped out, I’ve had that trouble this season. Also note the Ultra does require a Cleaning where you must pull it all apart. Check YouTube videos on that. I’m also a Boiler Tech. TY. Norm28

ThomF

Steven P,

Have you ever resolved your problem? I am getting the same error message on my W-M Ultra. I'm assuming that the pump might be failing, but wondering if you discovered something different in your situation.

My boiler also heats an adjacent hot water heater. Thus it runs all year. I'm seeing this error message occasionally when the hot water heater is calling for heat. It clears, and then proceeds normally, but I'd like to figure out what the issue is before it gets worse.

HVACNUT

What your experiencing is a soft lockout if you dont have to reset the boiler.
What series boiler? With the series 3, you call scroll through and see what your supply and return temps are, on a space heat and domestic demand.
If you've got outdoor reset, the boiler will ramp to the max set limit. It could be as simple as a faulty supply or return temp sensor. That's why WM gives you a new set as part of their Ultra maintenance kit, which should be done annually.
When was the last time it was serviced/preventive maintenance?

ThomF

Havcnut,

i have a Series 3 boiler. I have a boiler serviced annually--most recently in February I believe, and have had a service guy out a week ago for the issue--which he wasn't able to resolve.

I don't know if he routinely replaces the supply and return temperature sensors, but when I looked over shoulder when he was reviewing the error message and settings, and then running the boiler through its paces, the temps seemed logical.

But, again, I'm getting that error message fairly routinely stating that the temperature is increasing too rapidly.

Thoughts?

HVACNUT

The maintenance on the Ultra involves removing the front plate and cleaning the HX with a tool offered by WM but it does not come with the kit. The maintenance kit gives you the sensors, ignitor, flame sensor, replacement hardware to remove and clean the burner, replacement front plate heat board, gaskets, etc.
If your guy isn't doing that, he's not doing you a service. If everything goes smoothly, the maintenance takes about 90 minutes.
On the series 3 there's an option to extend post purge time that might help widen the band between the supply and return temps.

hot_rod

The service should go like this

https://www.youtube.com/watch?v=Rp8C8VgFySc

If the sensors have been tested or replaced and the temperature is in fact rising too fast, either the pump or plugged HX should be checked. It sounds like a lack of flow.

ThomF

HVACNut and Hot Rod,

The service guy has cleaned my heat exchanger each year, but of course on the fire side of the exchanger. If the issue is a plugged heat exchanger, I assume the water side would need to be flushed or cleaned in some way.
My guess, however, is that the issue is the pump.
I've attached a few images. One shows the screen display of temperatures under lockout status. As I noted, this has occurred when the hot water tank calls for temperature--which only occurs a few times a day. The system is typically starting from cold, as shown by the temperatures. So I don't think extending the purge cycle would help.
The unit was installed almost 10 years ago, and the pump for the hot water system runs all year. So perhaps it is failing.
Make sense?

hot_rod

Aluminum block boilers can be sensitive to aggressive fluids and they require special formulated glycol and inhibitors. Some aluminum boilers ship with treatment for the water side.

Any pex or rubber tube in the piping?

If in fact the control is telling the truth and you are seeing high temperature across the HX, it is probably time to clean and flush.

Use a cleaner designed for aluminum blocks, Rhomar, Fernox and others blend a specific cleaner.

Run the boiler up to temperature so the cleaners work well, run for a day if possible.

I'd use a purge pump to get a good flow velocity through the boiler to flush out everything the cleaner loosened up. Flush into a white bucket or two to see what comes out. Just flowing fill water many not give you enough flow velocity to scrub all the passageways. A 1/2 hp purge pump is usually adequate to flush the block if you isolate it from the system piping.

Then make sure the fill water meets the boiler spec, hard and or high TDS water, high chloride levels should not be used. Buy or filter the fill water. Test it onsite or send it to a lab for analysis.

Lastly I'd add a aluminum friendly treatment after it is filled and purged. It will add a thin micron thickness film protect those cleaned, bare aluminum surfaces.

HVACNUT

Sentry X100 inhibitor for the Ultra. Offered by WM.

ThomF

No PEX, but there is a rubber bladder in the expansion tank, I assume. I've got an Amtrol expansion tank, which describes the diaphram as a "rugged, flexible diaphram of a material specifically compounded for long life in hydronic service--so perhaps it's not rubber.
Are you suggesting that the issue is more likely a plugged heat exchanger, rather than a bad circulating pump? I was inclined to start by replacing the pump, figuring that was the more-likely cause.

hot_rod

certainly no harm in checking the circulator pump. is it the original one specified by the boiler manufacturer? It should be that blcak colored Taco circulator for the boiler.

Usually circulators don't wear away, they either run or not

It's possible some vanes have worn or broken off, but unlikely.

Have the pump isolated, or drain down and remove the 4 bolts that hold the motor into the body to inspect. No reason to replace a cir pump that is still working properly. It's not unusual to get 20 or more years out of that pump if it is sized and treated properly

You may need to purge the system again after re-installing the pump if the pump does't have isolation valves around it.

Odds are much higher that the boiler has some sludge in it if it has never been cleaned and it was not filled with good water and a conditioner added.

I'd also make sure the system doesn't have a small leak causing it to take on fresh water occasionally.

The 118 supply, 97 return is right on the money and should not cause a temperature lockout, if correct?

Try Norms idea of lowering the DHW supply to 180 for the indirect.

ThomF

Actually, I was thinking the issue would be the DHW pump. I'm assuming the boiler circulator/pump doesn't run when hot water is called for. Am I wrong on this?

The hot water pump is a Grundfos (sp?) whereas the boiler pump is a Taco...

hot_rod

I think you are piped like page 54? if so that DHW pump #5, needs to be sized as per the instructions on page 56, as it has to flow the boiler and tank on DHW call.

What model number on the tank pump, the Grundfos shown as pump 5 on the installation drawing?

https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Weil-Mclain-383-500-734-User-Guide.pdf

ThomF

The DHW pump is a Grundfos Part#: 59896341. Its a UPS15-58FC. Flow Range: 0-17 GPM
Head Range: 0-19.5 ft
My boiler is a Ultra Series 3 155.
The chart shows a Grundfos 15-42; perhaps that's similar to the 15-58? The flow and head range above for the pump seem the same. If so, the pump curve drops off pretty quickly.
As I noted, the pump is set to its maximum position.
So, perhaps the pump is marginal for the application, and now has degraded a bit (or the heat exchanger shows some minimal pluggage.
Perhaps replace it with a different pump?
Service guy is coming back tomorrow morning...

hot_rod

It's a 155 not a 105 as the post indicates?

The black Taco pump, a 0011 I'd guess? I think it ships with the boiler.

If so the DHW tank cir pump needs to be at least that size, you need to add the pressure drop in the boiler and the tank to size that pump.

Here is the procedure, below the example sounds a lot like your setup?

If so that 15-42 is way undersized. So if this is all true probably the boiler has been running outside of the parameters Weil indicates.

Could be the boiler and or tank is getting a bit more restricted driving up the pressure drop, putting the small pump further behind.

The art of the troubleshoot. A good tech should be able to check and confirm all the sizing and actual operating conditions.

Be sure to have the correct I&O manual on site, you can download from the Weil site, here are a few pages dealing with sizing the circulators.

ThomF

Yes, it's a 155. The original post started with a similar issue with another boiler--I tagged onto it, rather than starting a separate post, since the issues sounded like they might be the same.

bill794

StevenP,
Just wondering if you were able to eliminate the TRTQ errors? I have had problems with TRTQ with two different Ultra boilers and have solved this problem with both of them. One thing I didn't see discussed here is that hot water residing outside of the boiler (in an indirect water heater or in a zone that has recently run, for example) can get pushed back into the boiler while it is starting up and cause a TRTQ error. I have some simple suggestions about your heating system. Let me know if you are still interested and I'll spend more time responding to you.

bill794

I decided to follow up and provide a little more advice about the TRTQ problem.
There is a simple way to make sure the zone circulators are working correctly. I'd recommend that you make up two 30 psi pressure gauges with female hose connections to verify circulator performance. You should easily be able to attach them to the purge connections on the suction sides of both zone circulators. When the zone is off, you'll be reading the water pressure in the system, which should be around 15 to 20 psi. The pressure should drop by a few psi when the pump turns on, because you are on the suction side of the pump. Measuring the pressure will allow you to verify that the pumps are working correctly, and it then allows you know whether the pump is running or not by checking the gauge. I find this to be much simpler than trying to measure the voltage across the circulator.
You have a Taco zone manager and are running the zone pumps from that. I assume the two thermostats are attached to the Taco. The Taco places a call to the U Control Priority 2 in the boiler through its end switch. If one zone is cycling on and off frequently and the other zone cycles less frequently, the water in the two zones will be at a very different temperature. If a call comes in from the less frequently operating zone, cool water gets pumped to the boiler and it starts its ignition sequence. If a call comes in from the other zone within the first 2 minutes, it then pumps hotter water into the boiler loop and that causes the boiler's water temperature to go up quickly and trigger a TRTQ error. The Taco does not have the ability to coordinate calls coming from the two different zones.
One other thing I notice about the plumbing is that there is a common supply line running to the right out of the picture. I don't know how long the two zones share the same supply line? If the shared line goes some distance, then what will happen if one zone runs, then stops for a little while and the other zone turns on is that cool water from the second zone will first enter the boiler loop and then hot water that is in the shared supply line will get injected. That is another possibility for what's causing the problem you're seeing.
There is a (fairly) simple fix! Since you only have two zones, I would eliminate the Taco and run the two zones from Priority 2 and Priority 3 of the U Control in the boiler. Making this change is fairly simple, it just requires running the two zone circulators from the circulator relays in the U Control and hooking the two thermostats to the U Control P2 and P3 inputs. Then you'll need to program P2 and P3 in the U Control. If you program pre-purges into P2 and P3, (I would start with a 60 second pre purge) any call for heat will start by circulating water through the zone and the boiler loop, and then the boiler will begin the ignition sequence. If the boiler hasn't fired yet, it ignores any fast increases in temperature. The pre-purge can be a long as 4 minutes, but I doubt it would need to be that long to get rid of the problem.

ThomF

Bill,

I was able to resolve the issue. After checking everything, the local heating contractor changed out the main circuit board. The system has been working flawlessly ever since.

I do appreciate your analysis. I frankly don't understand why the TACO pump is needed, although I think the system really has three zones (two for heating and one for hot water).

As an aside, I purchased a 10 year warranty when the system was installed. The installer said that if the main circuit board failed, it would pay for itself. As it turns out, the issue first occurred before the expiration of the warranty, but it wasn't diagnosed until a few weeks later. The heating contractor wasn't able to cover it via warranty, but provided a free annual inspection as an offset.

I'm just happy to have a reliable system again.

bill794

Thom,

Glad you resolved the problems with your boiler.

My comments were really addressing the problem that StevenP described at the start of this chain of discussion. He actually posted the problem in 2018, so its likely he either resolved it or decided to just ignore it.

Good luck,
Bill

bill794

These comments should be added to my post from yesterday about Weil McLain Ultra 3 (and 4)105 auto reset errors. (Temp rising too quickly)

StevenP provides the U Control program above. While a 90 second post-purge is programmed into the U Control, because the zone circulators are powered from the Taco Zone manager and not the U Control, it is likely that all this post-purge is doing is operating the boiler loop pump and not the zone pumps. This is a problem that occurs when using a Taco zone manager to collect calls from one or more zones and feeding them to the U Control. The zone manager shuts off the zone circulator when the call from the thermostat ends. That is one of the reasons that I recommended hooking up a pressure gauge as a simple way to see when the zone circulators are running. And running all the circulators from the U Control for a 2 zone system.

Further down the string, StevenP suggests making the pre-purge longer. Extending the pre-purge would be a good thing to try, if he hasn't already done that. I'd start by making the pre-purge 4 minutes, and see if that makes the error go away. If that worked, it is easy to shorten it. Right now, the pre-purge is 30 seconds, and the TRTQ error is occurring near the start of the ignition sequence. That suggests that it would not take much of an additional delay to get the temp rise to take place before the ignition cycle starts.

StevenP didn't say the the overall error count was. The U Control fully logs the last three errors, but also keeps track of the total count. I've seen situations where the error count was in the 100's or errors if these auto rests have been taking place for a couple of heating seasons and they happen a few times a week. The total count would help determine how long the problem has been going on for.