First post - Danfoss help?

[MolehillMike]

Hi There,

I've browsed DIYnot.com for answers before, but with this particular issue I thought it made sense to sign-up.

I am not a plumber or sparkie... but I am capable of most DIY jobs.

Here is my Danfoss issue at the moment.

After a power outage over the weekend our boiler (Ideal Heat 12) appears to be being called all the time (by the lounge thermostat via the RX1).

So, after much Googling last night I know that we have:

1 x RX1 (with PROG and CH1 buttons)
2 x PMVs (One which controls the lounge heating, one which controls the rest of the house)
1 x RET B + RF (Lounge controller)
1 x TP5000SI-RF (rest of the house)

What I cannot work out is how both thermostats are paired, when they both appear to run to CH1? I tried to re-pair the RET B + RF last night but this morning we awoke to a lounge at 29°C, when I had the wheel LCD set at 18°C

I've turned our boiler off today as it was getting ridiculous. The temperature on the TP5000SI-RF showed 24.5°C, due to the heat from the lounge and I know the TP5000SI-RF is working as the rest of the radiators in the house were off this morning, and I set the temp on that to be 10°C to prove it was not at fault.

I believe we have 2 Port Motorised Valves, each controls either the lounge or the rest of the house, but they are both linked to CH1.

I've downloaded manuals for the various controllers, and they talk about pairing, and how to do it. Trouble is how do pair my individual thermostats to the individual PMVs, when both appear to be connected to CH1?

Please help!

 

[doitall]

Probably quite simple.

Likely. One room stat control one MV and the other room stat controls the other MV.

The end switch in both vlaves (orange wire) then controls the boiler

CH1 just puts an call signal to both stats

 

[MolehillMike]

Probably quite simple.

Likely. One room stat control one MV and the other room stat controls the other MV.

The end switch in both vlaves (orange wire) then controls the boiler

CH1 just puts an call signal to both stats

Thanks for that. So both valves can be wired to CH1, at least I know there hasn't been a mistake there.

So both stats can be paired to CH1, how does the RX1 know which valve to control from which stat, if they are paired to the same CH1.

How do I resolve my overheating lounge?

Thanks for your help.

 

[MolehillMike]

Probably quite simple.

Likely. One room stat control one MV and the other room stat controls the other MV.

The end switch in both vlaves (orange wire) then controls the boiler

CH1 just puts an call signal to both stats

Thanks for that. So both valves can be wired to CH1, at least I know there hasn't been a mistake there.

So both stats can be paired to CH1, how does the RX1 know which valve to control from which stat, if they are paired to the same CH1.

How do I resolve my overheating lounge?

Thanks for your help.

I have a sneaky suspicion my pairing from the lounge stat isn't linked. I did try this last night with the wife upstairs and me downstairs... as it's battery powered I think I will take a look myself with the stat upstairs and see if I can link them. Seems strange though that with no link the heating would just be on full pelt.

 

[doitall]

Ch1 just calls for heat, if the stat is satisfied then it wont open the valve.

There's many way it could be wired depending on the MVs (how many wires do they have).

 

[MolehillMike]

OK, thanks for that info.

Will grab some pics later... I have the builders electrician meeting me at the house at lunch. Will report back

 

[Justin Passing]

This all worked before the power outage??

One of the specific ways the Danfoss system (TP5000, RX-1) fails is that it will appear to work at the transmitter end, but only turn the boiler ON, never OFF.

If you have more than one transmitter working with one receiver it's going to be confusing, so try one at a time.

Start with the transmitter set to a low temp, unpaired, then pair it. Boiler should stay off.
Then turn the temp up and the light on the receiver should blink, and the boiler come on.
Then turn the temp on the transmitter down. (Symbol will go out on the transmitter).
If the receiver/boiler stays on, you've found your problem.
It points to the transmitter being faulty, but could be the receiver. I've only ever changed the pair together.
Worth changing the batteries in the transmitter first, of course.

The wiring - could be right or wrong, but if it worked before the problem's elsewhere.

 

[MolehillMike]

This all worked before the power outage??

One of the specific ways the Danfoss system (TP5000, RX-1) fails is that it will appear to work at the transmitter end, but only turn the boiler ON, never OFF.

If you have more than one transmitter working with one receiver it's going to be confusing, so try one at a time.

Start with the transmitter set to a low temp, unpaired, then pair it. Boiler should stay off.
Then turn the temp up and the light on the receiver should blink, and the boiler come on.
Then turn the temp on the transmitter down. (Symbol will go out on the transmitter).
If the receiver/boiler stays on, you've found your problem.
It points to the transmitter being faulty, but could be the receiver. I've only ever changed the pair together.
Worth changing the batteries in the transmitter first, of course.

The wiring - could be right or wrong, but if it worked before the problem's elsewhere.

Hi,

I will perform this test later but I know the RX1 is turning on and off (the CH1 light turns on and off when I pass desired temperature), but whether the boiler is then turning on and off is what I doubt.

Will update later/tomorrow when I here from engineer.

 

[Justin Passing]

the CH1 light turns on and off when I pass desired temperature)

Different problem, then. Voltmeter required.

 

[MolehillMike]

Cheers for the help here, and do not think it wasted. Some of the information above cleared up what was in my mind and allowed me to explain the situation to the site manager, who has just called me.

Seems he explained it to the Maintenance guy, and from that the maintenance guy went straight to the main box. Turns out two of the wires were fitted incorrectly (nothing to do with power outage), and the lounge thermostat had been working inverted, however because it was the showhome it wasn't obvious (as all doors were always open).

Once we moved in 10 days ago and actually started using the two thermostats differently it became clearer there was a problem.

Thanks for the pointers, and as I say it helped me to explain the problem clearly, so the expert could work a solution.