ACL Lifestyle 2-port valves – maybe failed – how to override? No DHW

[Clive]

Hi,

My immediate problem is no DHW.

I have searched this group and I think I have the following CH/HW setup

1.?Conventional? gas boiler i.e. Feeds a (poorly) lagged copper cylinder via an indirect coil from the boiler 2.Supplementary electric immersion heater in HW cylinder 3.Two 2-port ACL Lifestyle valves controlled by the Honeywell controller 4.Various water tanks in the loft

Now, various pipes connected to the HW cylinder are scalding hot but the HW delivered at the taps is tepid.

I am thinking the 2-port valve on the HW side has failed. I haven't yet traced the various water pipes and I need to study more about how such a system is connected and should operate (and fail) but I need help on the following.

I am guessing I can determine if the problem is a failed motor / valve by ?forcing? the valve open while the HW setting on the controller is on. Now, the problem is, I can't find any online information about the ACL Lifestyle valve. Does anyone know these devices? There is a little black ?switch? on top of each valve ? I would have thought this was a manual override to open or close the valve but the bit of plastic just ?waggles about? when I fiddle with it ? certainly there is no feeling that a switch is being operated that might cause a motor to open or close a valve.

If I can force the valve open and satisfy myself the motor is the problem does anyone know of a supplier for the ?actuator? part of the valve? I can't find online a reference and I guess it is an obsolete device.

If I can't override the motor, can I detach it from the valve and use a screwdriver to force the valve open?

If by trying to override the valve I determine the HW problem (probably) isn't due to the valve, what else might be worth looking at?

Naive question. Are the 2-port valves on the boiler / supply side of the circuit or the ?demand? side of the circuit? I am thinking they should be on the demand side to enable either circuit to be switched independently ? giving independent HW and CH. I can understand the operation of a 2-port valve on the sealed loop that goes around the radiators but I can't understand how such a valve would work on the HW side. Surely the DHW just comes off the top of the HW cylinder ? and the water removed is replaced by cold water supplied from the tank in the loft. So what flow is the second 2-port valve controlling?

[Clive]

A bit more info.

I think these ACL valves are now supplied by Invensys

On the Inversys Web site is a clear, simple diagram showing the setup (maybe a bit simplified) of a fully pumped system, with two motorised (zone?) valves.

The order of components in their diagram is: Boiler > Pump > T-connection > 1. 2-port valve on flow to HW cylinder and 2. 2-port valve on flow to radiators

Now on my system the pump is "upside down" i.e. pumping top to bottom and the valves are below the pump. This configuration "feels" weird to me but may be perfectly OK.

I have noticed there is a little "lever" to the side of the valve motor that barely protrudes and certainly can't be moved by me pushing with my finder tip.

One of the "tags" at the top (bottom?) of the valve motor I slid to one side and it has now "fallen" flush with the valve motor body. this tag can no longer be moved and I don't want to break it by fiddling.

This info is just to describe a bit more about the setup in case someone can help explain how to diagnose / fix the HW supply problem short term or long term.

Thanks

Clive

[geoff]

In message , Clive writes

The ACL Lifestyle actuator heads use standard synchron motors available fairly cheaply from most CH suppliers

If your actuator head has microswitches in it, check them out, they often go high resistance, if they haven't melted

[PM]

Naive question. Are the 2-port valves on the boiler / supply side of the circuit or the ?demand? side of the circuit? I am thinking they should be on the demand side to enable either circuit to be switched independently ? giving independent HW and CH. I can understand the operation of a 2-port valve on the sealed loop that goes around the radiators but I can't understand how such a valve would work on the HW side. Surely the DHW just comes off the top of the HW cylinder ? and the water removed is replaced by cold water supplied from the tank in the loft. So what flow is the second 2-port valve controlling?

*****

My setup is: Boiler flow > pump > 2-port valves > HW/CH > boiler return.

The HW 2-port valve is controlling flow of water from the boiler through the indirect coil in the HW tank.

The lever that you mention in your other post is to manually open the valve. They latch in the open position. If the valve is already opened by the system the lever moves freely, otherwise a bit of force is required. When the valve is open the boiler should fire.

[Roger Mills]

Have you still got the problem, or have you fixed it?

What you have is a fairly conventional S-Plan system. See the S-Plan section of

for a schematic and circuit diagram - which help to explain how it's supposed to work.

The bit you're missing in your question is that the HW cylinder is actaully a heat exchanger. It has a coil of pipe inside it through which water from the boiler flows, and indirectly heats the actual domestic hot water without any mixing of the primary and secondary circuits.

The primary circuit works as follows: Water heated by the boiler flows through the pump and then splits into two sub-circuits - each controlled by a zone valve. The CH sub-circuit goes through the radiators, and back to the boiler. The HW sub-circuit goes through the indirect coil in the HW cylinder and then back to the boiler. [The two returns may well combine into a single pipe before they get to the boiler].

As far as controls are concerned, the CH zone valve is controlled by the programmer and room stat, and opens when there is an unsatisifed demand for heating. Likewise the HW zone valve is controlled by the programmer and cylinder stat, and opens when there is an unsatisifed demand for HW. Each zone valve has a secondary micro-switch - not connected to the motor circuit - which closes when the valve is fully open, switching on the boiler and pump. [So the boiler and pump run when there is a demand from either or both circuit, and switch off when both demands are satisfied].

If you're not getting any hot water, it almost certainly means that the HW zone valve isn't opening, and isn't turning on the boiler and pump . This might be for any of a number of reasons:

• Faulty wiring from the HW output of the programmer to the cylinder stat and zone valve

• Duff cylinder stat

• Zone valve failing to open because of a duff motor in its actuator

• Zone valve opening but not turning on the boiler and pump due to a duff microswitch [Not very likely because the HW would still be heated whenever the CH is on]

• Zone valve failing to open because the mechanical part of it is seized.

Armed with a mains voltmeter, you should be able to find out whether the valve motor circuit is powered - and check back through the cylstat etc. if it isn't. If it is powered, but still doesn't open, remove the actuator - whilst leaving it connected electrically - and see whether that moves when it's not on the valve. If it does, it's a seized valve. If it doesn't, it's a duff motor.

To answer your question about over-riding the valve, the manual lever on some valves opens the valve but doesn't move it far enough to operate the microswitch - so the boiler still doesn't come on. I don't know whether yours is like that. If you open the valve by rotating its spindle with the actuator removed, that won't turn on the boiler unless the microswitch in the actuator also closes.

HTH!

[Clive]

More a "problem gone away" situation. The Invensys Web site has a simple, and thinking about it obvious, diagnostic routine. Basically shut CH and DHW to OFF and set thermostats to low temp. The seperately switch on CH and DHW circuits and turn at cylinder and room stat until see valves open, pump start and boiler fire. This now happens reliably. At least I now have a better understanding of how this all works.

All makes sense and a good checklist if the DHW goes off again

Again - makes sense now.

Ta

Clive