Biasi Riva Plus (m135.30cm) - Troubleshooting

[Philip Smith]

Hi, we recently bought a home with a Biasi Riva Plus (Combi) and have had a lot of problems with it. The service techs seems to have just as much trouble with it. I've done some troubleshooting myself since it stops working not longer after the service tech leaves. I'm quite mechanical but have no experience with these systems.

The first issue I ran into was that the pressure switch for the fan would not work because there was too much pressure in the furnace area to activate it. I tested this by removing the furnace cover and running the unit. Everything was fine until it was closed up again. I tried removing a few screews and could hear the air sucking in. I then attached a vacuum line to the other side of the pressure switch and ran it to an outside port so it had a neutral pressure. This fixed most of the recent problems, except for one:

The primary problem I have now is that the unit will occasionally not turn on. The reason is that the fan does not kick in. I've found that if I tap the circuit board area with my hand when the unit is in startup mode that the fan will kick on and everything will function properly for quite a while. My guess is that there is a switch on the Fan and APS Device circuit board (BI1555108) that is faulty. Either that or it is the primary circuit board? Any ideas?

The unit is 5-6 years old, model number m135.30cm.

I have gone through the unit and cleaned the electrical contacts and put Dielectric grease to help aid the connections, but no help.

 

[picasso]

So you have managed to bypass a safety device (the air pressure switch) I would strongly advise you to turn your boiler off and find a better service tech.

 

[snes]

If you electrically isolate the boiler, then you can look very closely (a magnifier helps) at the solder joints on the pcb. Its not unknown for the solder joints to detach from the board electrically while still looking sound. If you get lucky, you can simply resolder the joint.

If not, follow picasso's advice. You need a good boiler repair man, not a parts swapper.

 

[Agile]

They call them furnaces there!

 

[Philip Smith]

It seems like there are multiple issues that have been going on with the boiler. Since there seem to be multiple issues, it is hard for the repair person to figure out which things are not working. Here's the history:
The boiler did not work the first day we owned our new house. Fortunately we found it before the sale so the seller said they would take care of it.

They called the initial installer and he spent several days trying to figure out what was wrong including calling tech support to troubleshoot the unit. He cleaned the whole unit, replaced the pressure switch and got the unit up and running. However within a week it started working intermittently (I kept having to restart it to get it to work) and finally refused to run. I called the guy again and he came out and cleaned the whole thing out again which seems to have worked... for a couple months. (The problem is that the flames were pulling off the burners right where the heat sensor was so it would keep trying to relight itself.) The next time I called a repair person from the local Propane company thinking that they might know better how to repair the unit. They cleaned it all out, made some burner adjustments and then it works for another couple months. Lastly we had our domestic hot water not working. The boiler for heater the house would work, but not the DHW. I called a guy out and then it would not duplicate it for him. After a week or so the problem got so persistent that I had to call the repair guy again. It seemed that if I warmed up the boiler by heating the house, then the domestic hot water would work. The repair person changed out the thermometer for the DHW to fix that issue, and then found that the exhaust seal was leaking and causing exhaust fumes to recirculate in the unit which was causing the dirtiness in the combustion chamber and the flames to pull off the burner. He got it working and left, but said that he may need to replace the pressure switch and add some high temp sealer to the gasket that he re-positioned. The next day it would not run. This is when I tried to figure it out and did my tests with the pressure switch. I am willing to call the tech again, but I feel like they don't know much more than myself outside of calling tech support. That is why I am trying to troubleshoot it as well rather than having them spend all day at my house trying to figure it out.

Picaso - on your comment I am a little confused. I thought the pressure switch was for the purpose of telling the unit if the blower/fan was working so that it would fire up. Either you miss understood what I did or the pressure switch serves two purpose: 1) telling that the blower/fan is running and 2) telling that there is too much vacuum in combustion area. Is this correct? If so, then the problem I may now be having is some type of obstruction in the intake tube that is creating too much of a vacuum in the combustion area. This is the part that I bypassed by adding the additional vacuum hose. Am I understanding this right?

All this can help me when I talk to the repair person, so I appreciate your input and your time.

 

[Philip Smith]

By the way, I'm originally from California where "furnaces" were air heated and only had to deal with occasional freezing weather. Now I live in Maine with baseboard heaters and I'm not up to East Coast lingo. Do they call them Boilers or Furnaces? I have no clue. Thanks for your help anyway.

 

[Philip Smith]

Oh yeah, one more detail. The previous owner was an older single lady that said she had no issues with the furnace at all... no maintenance either in the 5 years she owned the house. After she moved out she was gone for a couple weeks and had the heat set low (in freezing temps) just before we purchased the home. The local propane company seems to show that she was telling the truth and had never had any service work done on the unit. So, it appears that something changed just before we bought the house... perhaps something with it being set low for a couple weeks, but not sure what.

 

[Agile]

We are in the UK with the Queen etc. You are in the US with that Obama guy!

You seem to be blaming your boiler because of an incompetent installer.

Here only trained and certificated people can install and repair gas appliances.

Your careless installer did not fit the flue seals properly and that caused flame lift off and he just did not recognise that.

But we are not allowed to give do it yourself repair advice on gas units.

Tony

 

[Philip Smith]

Thanks Tony. Here they have to be certified as well, but with so many different units, I don't think they are familiar with this one. I think this was one of the first propane boilers on the market here and not many people are familiar with them. The predominate boiler in our area is oil based.

Trust me, I'm not digging in any deeper to the repair, just looking for tips to pass on to the repair person now. Thank you for your help.

 

[Philip Smith]

The local service repair man came out yesterday to install the new Air Pressure Switch that they had ordered. I told him the situation with the boiler and the issues I was having. I helped him diagnose and troubleshoot the issues, and told him what things to check out. Long story short, there was a solder joint on the APS/Fan board that had been damaged which I was able to repair (he was not allowed to for insurance reasons, so rather than wait to weeks for a new one, he removed it for me and I repaired it), and there were rusty flakes of some kind in the intake which the service guy cleaned out. He said the flakes probably only accounted for about a 5% blockage and he didn't know why they would be there since the flue was galvanized. I said that maybe the flakes would peel up and block more air when there was movement. It turns out, so far, that everything is working great. Thanks for your tips and help.

 

[lordoftheflies]

Hello. I am in the US. One of my clients has a Biasi Riva m35.30CB (older version than this thread) and had intermittent issues where he would have to constantly run up to the boiler and turn it off and turn it back on. ONce the heating system reached temp it would then blow cold air. Two flashing lights with a solid red in the middle indicated that the ignition was not occuring properly.

Thanks to my conversation with QHT inc. and reading this thread, I determined over the phone that the APS/Fan controller board was most likely the culprit.

I arrived having never replaced one of these boards before - 2 screws on the front plate, 2 on the bottom, pull out the entire control panel, 3 more screws for the plate covering the main board and aps board. Had to shut off the central heat in the apart, reset the boiler one more time, and everything has been wokring perfectly.

Thank you to Philip Smith for posting this info. The part was out of stock but I managed to find a salesperson for QHT who had it in his travel kit. Woo hoo!

Thank you again.

 

[snes]

If you electrically isolate the boiler, then you can look very closely (a magnifier helps) at the solder joints on the pcb. Its not unknown for the solder joints to detach from the board electrically while still looking sound. If you get lucky, you can simply resolder the joint.

If not, follow picasso's advice. You need a good boiler repair man, not a parts swapper.

I'm feeling smug here......

Would have liked some appreciation though!

 

[lordoftheflies]

I'm feeling smug here......

Would have liked some appreciation though!

I apologize! Sorry I was talking on the phone AND typing the post at the same time and of course my brain got fried.

Thank you to everyone for your posts on this topic. They were all extremely helpful.

If you have any future issues I suggest you contact QHT Inc. here in the US. David Deblois (the customer service rep) was unbelievably knowledgeable and helpful as well.

Email: [email protected]
Phone: 1-800-501-7697
www.qhtinc.com

(I am not associated with them at all fyi)

Here are some pictures of the bottom of the defective APS/Fan controller board BI1555108 that I replaced. As you can see this board was beyond repair. Being in the northeast and in an unheated rooftop room I can see how condensation and the heatcycles could cause some condensation as well as expansion/contraction.

Compared to the new board:

 

[snes]

Hey, you're a real gent!

But my light hearted comments were aimed at the op, though I'm pleased that all comments on here helped you to a solution.

 

[Agile]

That is what we call a storage combi. Biasi ones are rarely seen in the UK.

The normal way to use them is to leave them on 24/7. The resulting heat loss from the hot store would usually prevent any condensation.

There should be a plastic cover on the top of the PCB box. I do hope yours is in place.

I would have expected to recover the old PCB.

Tony