Tarm Solo plus 60 high temp setting

[jw4984]

Hello, I moved into a house with a Solo Plus 60. Last year I fired it up for the first time. I had some success and some issues. I am a total noob so it was learning on the fly. And I am in RI where these units are not common.

Anyway, I just fired it up for the season. At times my oil burner kicks on even though the solo is at what I consider operating temp, 185-190 F. I don’t think this is supposed to happen (correct me if I’m wrong).

So my question is, what is the proper high temp setting? Right now my fan shuts off at about 186 F and then the temp creeps up to about 190 F. This seems perfect from reading the Manual which states optimal high temp to be at 185-190F. Would increasing the temp a bit help to avoid having my oil burner kick on?

FYI My system does not have turbulators nor do I have a thermal storage tank. Just a hydronic air system with an 80 gal indirect fired hot water tank. There is a dumb zone into my garage if the solo overheats.

Thanks in advance.

 

[peakbagger]

Sad to say you are going to be fighting this boiler until it get real cold or you put in storage. If you do try to use it during shoulder season it is going to be fairly inefficient and a creosote producer. Once your house heat load increases as it gets colder out and the rating of the boiler starts to match up with the house load it will run better. There is a reason that Tarm would not guarantee installations without storage in later years. Unfortunately they would sell the boilers without storage so there are many installations that were done without storage. I got my somewhat more primitive wood boiler for free and went through several seasons without storage. Luckily I had a wood stove so the boiler got relegated to heating the house up after I was gone for a few days or during the coldest weather in winter. Once I added storage, I started using it in shoulder season and stopped buying heating oil.

As for why your oil boiler kicks on, its highly dependent on how your controls are set up. My guess is the boiler heats up and takes care of the house load, the boiler will attempt to reduce its air supply to throttle back but will still heat up to high setpoint and dump to the garage until it burns it load out, then when the house calls for heat there is no wood in the boiler to burn and the oil boiler clicks on. On many wood boiler setups the wood boiler circulation pump is always circulating water through the overall system. If the wood boiler is not operating as its out of wood, the wood boiler becomes a heat load on the house sending heat up the stack. Depending on the controls, the oil boilers aquastat may run the oil boilr to keep the water in the loop hot.

Start budgeting for storage tank or only run it when you are home and manually turn off the burner switch on the oil boiler or put a relay on the oil burner so its locked out when ever the wood boiler is above some low setpoint. I installed a relay on my oil boiler that locked it out whenever the wood boiler was in operation.

Good luck, this Tarm is great piece of equipment but it cannot overcome a bad system design.

 

[Hydronics]

Those operating temps are fine for high point settings and the oil boiler should NOT be starting. It sounds like an issue with water flow from the wood to the oil boiler (assuming it's a boiler not a furnace). The lack of a storage tank is not ideal but it has nothing to do with the current issue.
Is the circulator from wood to oil flowing at these temps? If it is check your thermostatic mixing valve on the wood boiler it may be stuck and not allowing flow out of the wood boiler. The valve protects the boiler from cold return water below 140* which can cause local corrosion.
Once you get the water flow addressed you'll be impressed with the heat output.

 

[jw4984]

Those operating temps are fine for high point settings and the oil boiler should NOT be starting. It sounds like an issue with water flow from the wood to the oil boiler (assuming it's a boiler not a furnace). The lack of a storage tank is not ideal but it has nothing to do with the current issue.
Is the circulator from wood to oil flowing at these temps? If it is check your thermostatic mixing valve on the wood boiler it may be stuck and not allowing flow out of the wood boiler. The valve protects the boiler from cold return water below 140* which can cause local corrosion.
Once you get the water flow addressed you'll be impressed with the heat output.

How do I test the circulator pump? I don’t hear anything from the pump but I just assumed that was normal. Maybe it isn’t

The mixing valve is about 11 years old. I’m not sure if it’s working properly. I actually bought a replacement last year because the one installed is really discolored from the antifreeze in my system. However I didn’t get the new one installed because it’s a slightly different layout and I was having trouble finding someone who would reconfigure the piping. The job doesn’t seem that difficult but the guy I brought in didn’t feel comfortable.

Is there a way to test the mixing valve?

The oil boiler definitely kicks on a lot less when I am burning the solo. But it also kicks on periodically when the solo is at operating temp.

 

[maple1]

Hard to tell sometimes without being there. We cant see how the whole system is plumbed or all the controls are set. Could be a control issue. But also some systems need manual intervention when heating season starts (my parents system needs a valve turned when starting wood use so wood heated water will go to the oil boiler - then turned back when wood season is over so oil heated water wont go to the wood boiler).

 

[mustash29]

Some pics of your boilers, piping and controls may help with troubleshooting.

If the oil boiler is not set up for cold start, it may just be firing to maintain its low setting even though the Tarm is carrying the heating load.

 

[jw4984]

Some pics of your boilers, piping and controls may help with troubleshooting.

If the oil boiler is not set up for cold start, it may just be firing to maintain its low setting even though the Tarm is carrying the heating load.

Here are a few pics. The first is the back of the tarm showing the circulator pump and mixing valve (the discoloration on the mixing valve is from the antifreeze in my system) , the second is the loop to the oil boiler, just to point out there is a shutoff on the bottom connecting pipe and just above the oil boiler in the loop. The previous owner told me to open those when the tarm is burning and close them for the summer.

The last picture is of my tarm control panel

 

[jw4984]

I have been tinkering. I also called tarm. Seems like I have to lower my oil boiler aquastat from 180 to 160f when using the wood boiler. That way the oil boiler won’t kick on when the wood boiler is heating the water to 170-180.

This sounds good to me. What do you guys think?

 

[peakbagger]

I have the instruction manual from two older boilers and they both recommend the same thing. The problem is if the oil boiler is always kept hot (most are), the wood boiler circulator pump either runs 24/7 or might have a low temp cut off. When wood is not being burnt that circulating water runs through the wood boiler and give off heat to the stack and then return to the oil boiler cooler that will cause the oil boiler to fire even if there is no heating demand so the oil boiler is effectively heating up the stack via the wood boiler until the power is turned off to the wood boiler. With most of these systems there is no way to lock out the oil boiler from running as they use same thermostats and circulators as the oil boiler. I luckilly have a cold start oil boiler so with a lot of relays and valves I avoid that.

 

[jw4984]

I have the instruction manual from two older boilers and they both recommend the same thing. The problem is if the oil boiler is always kept hot (most are), the wood boiler circulator pump either runs 24/7 or might have a low temp cut off. When wood is not being burnt that circulating water runs through the wood boiler and give off heat to the stack and then return to the oil boiler cooler that will cause the oil boiler to fire even if there is no heating demand so the oil boiler is effectively heating up the stack via the wood boiler until the power is turned off to the wood boiler. With most of these systems there is no way to lock out the oil boiler from running as they use same thermostats and circulators as the oil boiler. I luckilly have a cold start oil boiler so with a lot of relays and valves I avoid that.

Thanks for the reply.

How do you tell if you have a cold start oil boiler. Mine is a buderus luongo g115 if that helps.

 

[Bad LP]

My LP boiler has a zone valve that was installed with the wood boiler. No water is running thru it but I do forget how the call for it to fire is broken.

 

[maple1]

Thanks for the reply.

How do you tell if you have a cold start oil boiler. Mine is a buderus luongo g115 if that helps.

If it goes & stays cold & doesn't fire, until there is a heat demand, it is cold start.

If it fires to keep itself warm even when there is no heat demand, it is not cold start. Or, it could be capable of cold start but isn't set up or controlled to.

I suspect your Buderus might be cold start capable, but not 100% sure.

 

[peakbagger]

If the boiler leaks all over the floor with the power turned off when it gets cold, its not capable of being a cold start unit. If it has a tankless hot water coil it unless you have another source of hot water like a remote tank you have to run it hot. Most installers go with a hot system unless there is good reason not to as its better for the boiler

My nieces setup is like yours, they just have a switch wired into the oil gun circuit that keeps the gun from firing until the wood boiler is cooled down enough that the wood boiler circulator stops running.