No hot water when heating is on

[GaZaai]

Hi all,

I have a Trianco Eurostar combi 65.

When the heating is on, I am unable to get hot water. If I set the thermostat to low temp to turn heating off I can hear the CH valve turn to hot water and it comes through.

What’s the issue here? I am getting 230v on terminal 2 when the tap is flowing so I guess the flow valve works but maybe wired wrong?

It’s just had a new CH valve fitted.

Thanks

 

[oilhead]

Get you fitter back to check his work. Have you had a complete new valve? Get him to check he has used the correct actuator. I don't think the original is available any more but the normal mid position actuator can be used but wires differently.

 

[GaZaai]

Get you fitter back to check his work. Have you had a complete new valve? Get him to check he has used the correct actuator. I don't think the original is available any more but the normal mid position actuator can be used but wires differently.

The boiler was installed back in 2004 it’s never had this functioning. So wouldn’t be able to get the original fitter and yes it was a brand new valve I put on yesterday. All part numbers were same as original and wired the same as well.

 

[EAST61]

Well there you go.

 

[GaZaai]

Well there you go.

There you go what?

New 3 way valve and motor, flow switch appears to work. Just wondering if anyone would know why it wouldn't work?
What wires to check etc

Thanks

 

[oilboffin]

How can you not get hot water the valve is set to hot water as default and has to move to supply heating so if the valve fails it fails to hot water so even if you have no heating you should always have hot water.The primary duty of a combi is for hot water.Bob

 

[GaZaai]

How can you not get hot water the valve is set to hot water as default and has to move to supply heating so if the valve fails it fails to hot water so even if you have no heating you should always have hot water.The primary duty of a combi is for hot water.Bob

If you read my question. I HAVE hot water ONLY when the central heating is off. I have to put the thermostat down low to get hot water or wait for the house tempature to reach the thermostat temp then I’ll get hot water.

When I put on the tap when the Thermostat is set high you don’t get any hot water through as the valve doesn’t turn automatically

 

[Terrywookfit]

Is the flow switch operating the relay ?

 

[GaZaai]

Is the flow switch operating the relay ?

Yes the relay is operating when I turn on the water

 

[oilhead]

Are you saying that since 2004 you have had this problem? If it has only appeared since you changed the valve, are you sure you have EXACTLY the same numbers? If you have used a HSA3 instead of HSA3CD, you are likely to get the problem you have.
The default position for the valve is for hot water, and only gives heating when hot water is satisfied. Yours is wired with a feed to open the valve all the time.

 

[Terrywookfit]

Are you saying that since 2004 you have had this problem? If it has only appeared since you changed the valve, are you sure you have EXACTLY the same numbers? If you have used a HSA3 instead of HSA3CD, you are likely to get the problem you have.
The default position for the valve is for hot water, and only gives heating when hot water is satisfied. Yours is wired with a feed to open the valve all the time.

From memory there were only 2 wires. The valve was open or closed.

 

[Terrywookfit]

Is it the variant with one or two relays. I think one was the Eco

 

[GaZaai]

I have had this problem since 2004 yes. No idea why I want to fix it now lol. The old 3 way valve was leaking so it had to get changed, the part numbers are identical.

So just to clarify the central heating works perfectly, nothing wrong with it. I only have an issue where the boiler doesn't turn to hot water when the heating is on (as in radiators are warm and thermostat is say set to 21 degrees). So if someone was to wash there hands they wouldn't get hot water if the thermostat was set high.

Also I only have one relay on this model it is an ECO

 

[Terrywookfit]

Flow switch operates.....mains on T2 and operates relay...M/v closes.
SHOULD BE MAINS ON RELAY T11 & T 14 AND ALSO T21 & T24

 

[GaZaai]

Flow switch operates.....mains on T2 and operates relay...M/v closes.
SHOULD BE MAINS ON RELAY T11 & T 14 AND ALSO T21 & T24

Flow switch operates correctly
Mains is on T2
Relay operates
M/V does not close (this only seems to move when the thermostat is set to a lower setting, not related to hot water tap flow)

The T11,T14,T21 and T21 are harder to get to so cant test them just now but I've ordered a new relay anyway to put in and see what happens without altering wiring.