HSA3 Mid Position Valve Actuator Problems..

[alx]

Hi,

A few weeks ago, I had some issues with my heating. The fault was found to be a damaged cable in the Kitchen wall, which was repaired / replaced. At the same time I found the 3-way valve in the airing cupboard to be leaking when set for heating. For the last few weeks I have had the 3way valve actuator wiring disconnected and have just been using the system for hot water.

Today I finally got round to replacing the 3-way valve body and put a new (but not tested) actuator head on as the old one had visible signs of water damage.

I have wired everything up, but the boiler will not fire when only CH is called for by the programmer. Nothing trips out, the light on the programmer illuminates, and you can hear the relay click.. but nothing happens with the boiler. (I have checked and there is power getting to the wiring junction in the airing cupboard)

HW is working fine..

My assumption is that I have two faulty 3-way valve actuator heads, but before I buy another one to check, I was hoping someone could clarify if the actuator could cause that fault ?

My system is as follows;

Ideal Classic FF350
Salus EP200
Salus RT500
Danfoss HSA3
Danfoss Tank Stat

I have wired the HSA3 up as follows;

Blue - Neutral
Brown / White -Room Stat control
Grey - HW call from Tank Stat
Pink - HW off from tank stat

Thanks.. Alex.

 

[dcawkwell]

I don't mess around replacing heads. I do the job properly
and do the whole valve.

Buy a whole valve connect it in to wiring in place of the faulty
valve and see if it moves correctly when not in the piping.
If it does replace the whole valve with the new one.

To test for faults you will need a multimeter to do it properly.

 

[alx]

I have replaced the whole valve, as the old one was sticking and leaking.. The plumbing side of the valve is now working fine.

I also replaced the motorised head as the old one had visible signs of water damage..

The fault I have now is with the electrics of the system. I think I may have purchased a duff motor head, but would like to test it first, before I buy another..

I have a multimeter ready, just waiting on some advice regarding what tests to run..

Thanks.

 

[alx]

I've been poking around in the terminal box with the multimeter..

The feed from the the programmer for CH on is live when the programmer calls for CH. This is connected to another cable, which I can only assume returns to the boiler for the live supply.

The feed from the room stat is also live when the stat calls for heat.

My question is, does the HSA3 electrical wiring need to be connected in the junction box to complete the circuit for the CH ?

If not then my fault obviously lies elsewhere - potentially in the return supply for the boiler.

Thanks..

 

[alx]

As suspected, when calling for CH there is no live supply to the boiler.. (This is with the HSA3 wiring still disconnected)

Any advice would be most gratefully received.

 

[dcawkwell]

Manual for a 3 port valve can be found here.

http://www.honeywelluk.com/products.../V4073A-Motorised-Midposition-Diverter-Valve/

Can remember the actual wiring

something like

white hot water
grey hot water and heating

white and grey heating

Check your orange wire for 240 volts and the white and grey wires.

 

[alx]

Manual for a 3 port valve can be found here.

http://www.honeywelluk.com/products.../V4073A-Motorised-Midposition-Diverter-Valve/

Can remember the actual wiring

something like

white hot water
grey hot water and heating

white and grey heating

Check your orange wire for 240 volts and the white and grey wires.

Thanks for the reply..

Although similar, my system has a Danfoss HSA3, which has slightly different wiring to what is shown on the danfoss website.

My orange wire is connected to HW Call from the tank stat, but not looped into the boiler / pump live.. Maybe that is the issue ?

 

[MANDATE]

I'm fairly sure the wiring for your 3 port valve is the same as for the honeywell.
Basically there are 3 wires leaving the programmer (ignoring any neutrals or earths)

Wire (1) comes from the HW ON terminal, (goes via junction box) to cylinder stat, then across the stat, then from cylinder stat (via junction box ) to boiler/pump.
When HW satisfied the stat will break the circuit.
As you have no problem with HW your problem lays elswhere.

Wire (2) comes from the CH ON terminal, (goes via junction box) to the input side of the room stat, From the output side of room stat (goes via junction box ) to the white wire of valve.
When room stat is turned up and white becomes live, the motor gets driven to mid position.
Note the CH and HW will now share the flow of water until one side becomes satisfied (usually HW) when the valve is then supposed to move to CH only.
To do this the power lost from the white wire is replaced with power on the grey wire (micro switch breaks white and makes grey)
The grey gets its power from one of two sources.
When HW gets satisfied the cylinder stat breaks contact to boiler and switches power to the satisfied terminal of the stat.
A wire from this terminal leads to the grey, which drives the motor forward to CH. While doing this a second micro switch allows power out of the valves orange wire to re start the boiler.
The power to start boiler then comes from cylinder stat if HW is involved or the valves orange wire if HW not involved.

It may be that HW is not on so the grey would not become live and this is where the second source comes in.
Wire (3) A wire is used from the HW OFF terminal of programmer to join the grey.
Note the grey cant do anything till the valve is in mid position and that depends on the white.
Question is? does valve stay put at HW or does it move to mid position?
I had fault, where valve moved as it should, but no output from orange (faulty micro switch)
Hope it helps

 

[alx]

I'm fairly sure the wiring for your 3 port valve is the same as for the honeywell.
Basically there are 3 wires leaving the programmer (ignoring any neutrals or earths)

Wire (1) comes from the HW ON terminal, (goes via junction box) to cylinder stat, then across the stat, then from cylinder stat (via junction box ) to boiler/pump.
When HW satisfied the stat will break the circuit.
As you have no problem with HW your problem lays elswhere.

Wire (2) comes from the CH ON terminal, (goes via junction box) to the input side of the room stat, From the output side of room stat (goes via junction box ) to the white wire of valve.
When room stat is turned up and white becomes live, the motor gets driven to mid position.
Note the CH and HW will now share the flow of water until one side becomes satisfied (usually HW) when the valve is then supposed to move to CH only.
To do this the power lost from the white wire is replaced with power on the grey wire (micro switch breaks white and makes grey)
The grey gets its power from one of two sources.
When HW gets satisfied the cylinder stat breaks contact to boiler and switches power to the satisfied terminal of the stat.
A wire from this terminal leads to the grey, which drives the motor forward to CH. While doing this a second micro switch allows power out of the valves orange wire to re start the boiler.
The power to start boiler then comes from cylinder stat if HW is involved or the valves orange wire if HW not involved.

It may be that HW is not on so the grey would not become live and this is where the second source comes in.
Wire (3) A wire is used from the HW OFF terminal of programmer to join the grey.
Note the grey cant do anything till the valve is in mid position and that depends on the white.
Question is? does valve stay put at HW or does it move to mid position?
I had fault, where valve moved as it should, but no output from orange (faulty micro switch)
Hope it helps

Very useful mate.. Thanks very much.

I'm going to double check the two valve heads that I have, to make sure I haven't missed something, but I expect them to both to be faulty.

Hopefully a new valve head will sort things..

 

[alx]

Question is? does valve stay put at HW or does it move to mid position?
I had fault, where valve moved as it should, but no output from orange (faulty micro switch)
Hope it helps

Refitted the Actuator. CH now fires the boiler, so I'm quite happy!

The actuator however, is remaining at mid-position when HW only is called for..

When the system is off, the actuator is returning to CH only too.. I'm sure it used to return to HW only ?

I guess that means its knackered ?

You can hear the microswitches ticking constantly when the system is fired up for HW only as the motor gets to mid position, it won't go any further ?

Could this be a wiring issue ?

Any further ideas other than replace the actuator again ?

 

[alx]

After much more messing about with this I've declared both valve heads to be knackered.. I had the system working at one point, which proves the wiring is correct if nothing else..

I'll get one ordered, and hopefully that will be the end of my problems..

Thanks for the advice..