Danfoss RMT230 Thermostat

[Dave1978W]

Hi, I ordered a replacement RMT230, but when going to replace the old one, my old thermostat has 3 wires whilst the replacement does not have the terminal for the Neutral wire (Blue) which goes to the accelerator.

My question is, can I simply make the neutral redundant? If so, what effect overall will it have on the heating system without having the accelerator? Will this have a negative impact on the performance?

Thanks in advance!!

 

[RayCaister]

It is the earth wire that is redundant not the neutral.

 

[Dave1978W]

Hi Ray, Yes, I have the earth already not in use, but I've read other threads where when 'upgrading' to a digital thermostat and only 2 wires are required, it has been stated that the blue should be taped off and left unused. I was wondering if it is the same in this circumstance?

 

[Dave1978W]

The first image is the same as mine wired. The second is what I have received and looking to replace the old one with.

Thanks

 

[RayCaister]

The live feed goes to the left most terminal (no.1?) and neutral to the right most terminal. The central terminal is un-wired.

 

[Dave1978W]

The live feed goes to the left most terminal (no.1?) and neutral to the right most terminal. The central terminal is un-wired.

Does not having an accelerator affect the performance of the heating system greatly? I have no clue of what the accelerator actually does!?!

 

[fixitflav]

The first image is the same as mine wired. The second is what I have received and looking to replace the old one with.

Thanks

According to this from the internet your old one has an accelerator but the new one doesn't. A bit odd they're both called RMT230. I can only assume they think the new one doesn't need it, perhaps they've reduced the hysteresis so no need for it. Neither has an earth connection. Both have a DT switch, but the satisfied contact 3 is unused.

 

[RayCaister]

I lifted this description from a previous poster ... Overall, the effect is to increase the on-off switching rate so that the room temperature is steadier. A lower rate would mean that the room fluctuates between hot and cold rather more.

All OK during most of the year when the full boiler output is not needed, but when you want it on full, the accelerator resistor is always on and lowers the operating temperature. Hence the average room temperature is colder in cold weather than when it's mild... I doubt you will know the difference.

 

[fixitflav]

I agree with

Overall, the effect is to increase the on-off switching rate so that the room temperature is steadier.

Don't know about

A lower rate would mean that the room fluctuates between hot and cold rather more.

A lower rate of what?

All OK during most of the year when the full boiler output is not needed, but when you want it on full, the accelerator resistor is always on and lowers the operating temperature. Hence the average room temperature is colder in cold weather than when it's mild

I don't follow that. The accelerator resistor is energised only when the stat is calling for heat.