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Hi, I am trying to understand the root cause of my radiators getting lukewarm at best.
I have an ecoTEC plus 428. It doesn’t display any fault codes, but it spends most of its time with the boiler off, displaying a blinking radiator. Seemingly, as a consequence, my radiators never get more than lukewarm.
My understanding is that the blinking radiator icon indicates that it is waiting for the temperature of the flow water to fall to a value that allows the boiler to restart without risking overheating.
I am a complete noob, so forgive my Dr Watson type attempts to resolve the mystery by gathering some facts and considering bits of evidence. Is there a Sherlock Holmes out there who can come to my rescue?
Looking in the diagnostics table I see that d.5 is the flow temperature target value. In my case this is set to 71 degrees (how this is determined and set, I don’t know and I am not sure it matters).
d.40 is the Flow Temperature – Actual Value
d.41 is the Return Temperature – Actual Value
So, taking my very simple-minded approach, I would expect the boiler to run until d.40 approaches or equals d.5 – in my case 71 degrees, at which point the boiler would moderate itself and if it went over-temperature, shutdown and wait until the temperature fell sufficiently to allow the boiler to restart safely.
I think this should happen relatively smoothly maintaining a constant flow of hot water through the central heating pump and radiators, until the radiators/thermostat stop calling for heat.
In my case, this is what happens –
1. The boiler runs, the radiator icon is solid, and the temperature displays 72.
2. d.40 rises rapidly to 71/2 degrees and the outflow from the central heating pump immediately gets hot.
3. d.40 then shows the temperature dropping to 63/64 degrees with the boiler still running, then after only a few seconds the d.40 temperature starts to rise rapidly again, this time getting to 73, at which point the boiler turns off. This on to off again takes no more than about 20 seconds.
4. d.40 rapidly (over a few seconds) declines to 50, matching d.41. That seems reasonable as the return flow cools the water in the boiler and the two values reach equilibrium.
5. After that d.40 and d.41 decline more slowly over a period of minutes. The central heating pump continues to run but its out-flow pipe is relatively cool as the boiler isn’t running.
6. At some point, with d.40 and d.41 at around 48 degrees, the boiler decides to restart and we are back to point 1., and the beginning of the cycle.
This behaviour matches the outcome I am seeing at the radiators. The first radiator in the chain gets hot, all the others at best manage to get a little warm. This is as a result of a short burst of hot water while the boiler runs followed by an extended period of water recirculation with the boiler off.
The fault seems to be at stage 3 of the process. Instead of the boiler running for an extended period managing the flow of water in the mid to high 60s and allowing the pump to circulate it, it shoots up to 72 degrees, comes down to the mid-60s for a few seconds, rebounds up to 73 and switches off.
Can anyone help me to understand what is going on?
Many thanks
I have an ecoTEC plus 428. It doesn’t display any fault codes, but it spends most of its time with the boiler off, displaying a blinking radiator. Seemingly, as a consequence, my radiators never get more than lukewarm.
My understanding is that the blinking radiator icon indicates that it is waiting for the temperature of the flow water to fall to a value that allows the boiler to restart without risking overheating.
I am a complete noob, so forgive my Dr Watson type attempts to resolve the mystery by gathering some facts and considering bits of evidence. Is there a Sherlock Holmes out there who can come to my rescue?
Looking in the diagnostics table I see that d.5 is the flow temperature target value. In my case this is set to 71 degrees (how this is determined and set, I don’t know and I am not sure it matters).
d.40 is the Flow Temperature – Actual Value
d.41 is the Return Temperature – Actual Value
So, taking my very simple-minded approach, I would expect the boiler to run until d.40 approaches or equals d.5 – in my case 71 degrees, at which point the boiler would moderate itself and if it went over-temperature, shutdown and wait until the temperature fell sufficiently to allow the boiler to restart safely.
I think this should happen relatively smoothly maintaining a constant flow of hot water through the central heating pump and radiators, until the radiators/thermostat stop calling for heat.
In my case, this is what happens –
1. The boiler runs, the radiator icon is solid, and the temperature displays 72.
2. d.40 rises rapidly to 71/2 degrees and the outflow from the central heating pump immediately gets hot.
3. d.40 then shows the temperature dropping to 63/64 degrees with the boiler still running, then after only a few seconds the d.40 temperature starts to rise rapidly again, this time getting to 73, at which point the boiler turns off. This on to off again takes no more than about 20 seconds.
4. d.40 rapidly (over a few seconds) declines to 50, matching d.41. That seems reasonable as the return flow cools the water in the boiler and the two values reach equilibrium.
5. After that d.40 and d.41 decline more slowly over a period of minutes. The central heating pump continues to run but its out-flow pipe is relatively cool as the boiler isn’t running.
6. At some point, with d.40 and d.41 at around 48 degrees, the boiler decides to restart and we are back to point 1., and the beginning of the cycle.
This behaviour matches the outcome I am seeing at the radiators. The first radiator in the chain gets hot, all the others at best manage to get a little warm. This is as a result of a short burst of hot water while the boiler runs followed by an extended period of water recirculation with the boiler off.
The fault seems to be at stage 3 of the process. Instead of the boiler running for an extended period managing the flow of water in the mid to high 60s and allowing the pump to circulate it, it shoots up to 72 degrees, comes down to the mid-60s for a few seconds, rebounds up to 73 and switches off.
Can anyone help me to understand what is going on?
Many thanks
