Radiator Thermometer Network

[KDMcM]

After I flushed my system recently and replaced a couple of the TRVs, I struggled to re-balance it. There were 2 rads which wouldn't warm up for ages after the rest. I had been unaware that my system would need re balancing. There must have been some serious crud in the pipes.

I learned on this forum that even TRV-equipped installations need balancing. The reason is still a bit fuzzy, but I think that basically if one of the radiators has as a low flow, due to blockages, air, pipe bends, or has a low incoming temperature and therefore doesn't heat up due to being far from the boiler, then one or more of the other TRVs has to close in order to increase the flow and incoming temperature. So, basically, some rooms will heat up while others remain cold until the first are up to temperature.

Anyway, that's not the point. In balancing my radiators, I've created a set of WiFi networked differential thermometers. I can see the flow and return temperatures of each of a number of radiators. monitoring this as the system is switched on tells me which lockshield valves to adjust. And, incidentally, if the TRVs are on the flow or return.

My setup can only do 3 radiators at a time presently, so there was a bit of jiggling involved in tuning my 12 radiators but the system could be extended to cover a dozen radiators for not a great deal of hardware cost. If I thought there was any value in it, I would also make the software a little more friendly.

For me, it was a fun toy. It seems a shame to dismantle it. Would such a thing be of any use to plumbers? Does the system have any commercial potential? Importantly, am I misguided in my understanding of the requirement to balance TRV-controlled radiators?

 

[oldbuffer]

1. The purpose of balancing is to ensure that a roughly equal flow of hot water is available to each radiator. In that way, if there were no TRVs on the system, all radiators would heat their rooms (assuming correctly sized) at approximately the same rate.
2. With TRVs fitted, if the system is not balanced, radiators getting most flow will heat up their rooms first, then shut off, allowing the heat to flow to the other radiators. Thus the heating of the whole property will not be evenly timed. In many cases it doesn't really matter, but if, for example, the living room were the last to heat, this could be an issue.
3. With TRVs fitted and the system balanced, all rooms should heat at roughly the same rate.
4. And I like your networked thermometer idea. I once thought of something similar, but with stepper motors for each valve to make the whole boring process automatic. But I decided it would be a waste of time and money. The rule of thumb, pragmatic, approach of adjusting them is quicker unless you want to be really accurate.

 

[D_Hailsham]

1. The purpose of balancing is to ensure that a roughly equal flow of hot water is available to each radiator.

Incorrect.

The purpose of balancing is to ensure that each radiator gets the correct flow, which is proportional to the output of the radiator. (Assuming the flow/return differential is the same.) So a 2kW radiator needs twice the flow of a 1kW radiator.

 

[KDMcM]

The purpose of balancing is to ensure that each radiator gets the correct flow, which is proportional to the output of the radiator. (Assuming the flow/return differential is the same.) So a 2kW radiator needs twice the flow of a 1kW radiator.

Assuming I were able to measure the flow and return temperatures of each radiator in a TRV-governed system, then, how would I know they were balanced?

 

[Madrab]

Assuming I were able to measure the flow and return temperatures of each radiator in a TRV-governed system, then, how would I know they were balanced?

Balancing, in simple terms means that you get all the radiators in a system warming up at the same time and reaching optimum heat transfer into the room, that is gauged by the temperature drop across the radiator. The system needs setup without the TRV's to start with and flow is controlled by adjusting the lockshield. Once balanced properly then it shouldn't need monitored.

Have a read at the Boiler and central heating FAQ's, FAQ 5 I think it is.