Heating question

[rodniy]

Hello.

Can someone please help me with my problem.

I recently set up heating in my house with Intelligent Room controllers and 1-wire temp sensors.

Basically for every room in my house (radiator connected to manifold on every floor) I set up a proportional 24V 0-10V actuator, controlled by temperature sensor and IRC. 

One example is below.

All of IRCs are connected to Intelligent Temperature Controller which controls the heating (one integrated unit, with gas furnace, boiler, manifold, pump,..).

Everything seems to work and I'm really happy about it. Until.. the last few days, my gas furnace shut down several times in some kind of error mode and needs to be restarted every time.

The manual doesn't help me much, because this can be caused by quite a few situations, so no chance for debugging there.

But.. I suspect that the cause is, that the boiler can't get rid of the excessive heat if all of the proportional valves close quickly. 

How can I prevent closing the valves if the furnace just stopped working. I tried inserting the switch-off delay component on the ITC output, but.. it's not proportional.

And another quick question. I don't understand the difference if I connect the heating to ITC or to Climate Control. They seem to do the same thing, no?

Thanks.

[Andras Gaal]

Hi,

Unfortunately I don't have an idea why you are seeing issues. I did exchange a few emails though with Loxone on the ITC vs. CC topic. Here's what I have found out:

• ITC starts immediately when there is heating demand (any of the connected room's heat load is above threshold - Str parameter)
• CC starts only when cumulative heating demand in connected rooms is above the Str threshold
• ITC reacts as soon as connected IRC's signal demand
• CC has an approx 1 minute delay

Here's an idea for your issue: while the switch-off delay is running (input != output on the switch) use an analog multiplexer and output a fixed value to valves for the switch-off delay period. For this reason, I am actually only taking the AQf from the ITC and starting the boiler and pumps with the CC.

[rodniy]

Hi.

Thanks, great idea.

I've just configured it.. after the heating stops, then I'm dumping the excess heat into some rooms for cca. 10min.

Hope it will work.

And .. what are you doing with AQf from ITC? 

[Andras Gaal]

I am taking the higher of the AQf's of the UFH and radiator ITC's and feeding it as a 0-10V signal to the boiler as an expected water temperature. I have a mixer valve in the UFH zone to decrease the temp (from up to 55 degrees) in case the radiator zone is also running. The mixer valve is essentially "open" when only the UFH zone needs heat, and the boiler is natively creating the up to 40 degree water.