Loud noise from 3 port valve

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vivs

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Hi All, recently had the three port valve replaced. It worked fine for 3 weeks, now it is making loud banging noise when central heating is turned on from controller and there is call from heat from central heating thermostat. Please listen to the video in the link. The noise disappears when the lever on 3-port valve is moved to middle and then back left to auto.Video

Any thoughts what this could be?
 
Thank you guys for getting back. A bit more context on the whole set up. This is how the system is intended to work - hot water turned on from controller would work on its own (if there is call for heat from thermostat on hot water tank). Central heating will only work if it is own from controller, hot water is also on from controller and there is a call for heat from room thermostat. (Central heating on from controller on its own is not designed to work). With this design, how A, B and AB from 3-port valve should be wired?

I am getting an engineer to look at in the morning as well.

Any insights will be useful. Thank you.
 
Bod ... said:
I will pay more attention in future.
Click to expand...
Thanks Bod, just so that I understand correctly (I am in pre-diy stage, so please pardon my ignorance) B into hot water cylinder and A into radiators is wrong way to do it?
 
vivs said:
Thanks Bod, just so that I understand correctly (I am in pre-diy stage, so please pardon my ignorance) B into hot water cylinder and A into radiators is wrong way to do it?
Click to expand...
That's correct


Where is the pump?
 
Bod ... said:
That's correct


Where is the pump?
Click to expand...
Pump is feeding into AB. Please read this as well. This is how system was working initially-A bit more context on the whole set up. This is how the system is intended to work - hot water turned on from controller would work on its own (if there is call for heat from thermostat on hot water tank). Central heating will only work if it is on from controller, hot water is also on from controller and there is a call for heat from room thermostat. (Central heating on from controller on its own is not designed to work).

There is a cold water tank and a small tank for heating system in loft.
 
If it’s plumbed in correctly, then I’d say could be motor not sat correctly
 
vivs said:
Pump is feeding into AB. Please read this as well. This is how system was working initially-A bit more context on the whole set up. This is how the system is intended to work - hot water turned on from controller would work on its own (if there is call for heat from thermostat on hot water tank). Central heating will only work if it is on from controller, hot water is also on from controller and there is a call for heat from room thermostat. (Central heating on from controller on its own is not designed to work).

There is a cold water tank and a small tank for heating system in loft.
Click to expand...

Just to confirm, AB is from the boiler FLOW (hot)?, B goes to cylinder & A goes to CH.

You say, above that "(Central heating on from controller on its own is not designed to work)." are you saying that you can't have CH on its own without the HW on and calling at the same time. If its a 3 port mid position valve then you can have HW only, CH only, and HW&CH together. (see user friendly schematic, below and "official" Y plan), if it a 3 port diverter valve then you can only have HW or CH but not both together. Can you confirm that you have a mid position valve via model number or photo?.
 

Attachments

  • Mid Position Valve Unmodified.gif
    Mid Position Valve Unmodified.gif
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  • Y Plan Wiring Schematic.gif
    Y Plan Wiring Schematic.gif
    57.4 KB · Views: 29
Johntheo5 said:
Just to confirm, AB is from the boiler FLOW (hot)?, B goes to cylinder & A goes to CH.

You say, above that "(Central heating on from controller on its own is not designed to work)." are you saying that you can't have CH on its own without the HW on and calling at the same time. If its a 3 port mid position valve then you can have HW only, CH only, and HW&CH together. (see user friendly schematic, below and "official" Y plan), if it a 3 port diverter valve then you can only have HW or CH but not both together. Can you confirm that you have a mid position valve via model number or photo?.
Click to expand...
thank you Johntheo5 for looking into this. Some observations below :-
1. Correct, AB is from boiler flow (hot). AB is fed from pump installed just below the AB.
2. Central heating only works when HW is also on from controller. This does not mean HW is called by cylinder, just on from controller. My understanding is that when central heating and hot water are both on from controller, hot water cylinder thermostats decides if there is need for hot water or not, and if there is no need for hot water, then it sends signal to value to move to central heating only. I am looking for wiring diagram to allow for this function. All this will not happen if hot water is off from controller. This is how system was working previously.
3. 3 port valve -

HONEYWELL HOME V4073A1039/U 3 PORT MOTORISED VALVE 22MM 22MM COMPRESSION​

 
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