Hot Water not lasting as long and radiators taking longer to heat up

[Adam Bill]

I have noticed that over the past month or two that my hot water is not lasting as long. I will run a very small bath for the children and have two showers and at the end of the first shower the water will go cold. In addition to this over this time I have also noticed that the heating also is taking much longer than it used to. I have noticed that the pump does sound noisy and is vibrating a bit but this has been going on for a lot longer than when these issues have.

Does anyone have and ideas as to what this could be or how I could fix it? The boiler is relatively new so I don't think it is that and the hot water used to last for the small bath and 2 showers and the heating was a lot quicker to get to temperature.

 

[Jurassicspark]

What type of system is it?

How many motorised valves?

 

[Adam Bill]

It is a conventional boiler with a hot water tank. I believe I just have the one valve

 

[CountryFan]

It is a conventional boiler with a hot water tank. I believe I just have the one valve

Valve could be stuck in mid position

 

[Adam Bill]

Would I need to get a new valve?

 

[CountryFan]

Would I need to get a new valve?

Or a new actuator, depends on age of the valve, type and whether the spindle has gone

 

[Adam Bill]

So I have had a look today and the valve is a Honeywell 3 port valve. There is a metal bit at the back that goes from manual to auto I have had a look at that and switches from manual to auto and it does not move on it's own feely back to auto which I believe it should do. Does this mean a new valve?
What is the valve not doing that it should be?

 

[CountryFan]

So I have had a look today and the valve is a Honeywell 3 port valve. There is a metal bit at the back that goes from manual to auto I have had a look at that and switches from manual to auto and it does not move on it's own feely back to auto which I believe it should do. Does this mean a new valve?

Not necessarily

What is the valve not doing that it should be?

If it’s stuck in mid position then it’s not allowing the full heat to either circuit.

 

[fixitflav]

If it’s stuck in mid position then it’s not allowing the full heat to either circuit.

It would be allowing heat to both circuits (whether called by the stats or not). I don't think that explains the symptoms, though I can't think of what does at the moment.

 

[Harry Bloomfield]

I have noticed that over the past month or two that my hot water is not lasting as long. I will run a very small bath for the children and have two showers and at the end of the first shower the water will go cold. In addition to this over this time I have also noticed that the heating also is taking much longer than it used to.

What temperature is the boiler output set for? Some boilers have a single boiler temperature setting for both HW and CH, others have separate settings for each mode.

To test the 3-port valve operation, the OP simply needs to turn on and off, in turn, the HW, then CH. He should then hear the actuator react, to the changes in demand. If the suspicion is that the actual valve itself might be stuck, and the actuator head is removable - he could remove the actuator and try turning the valve spindle back and forth. It should almost turn, with finger pressure, but a pair of pliers might be needed.

If the actuator head, is not responding by moving, a common fault, is the motor failing. They can be bought quite cheaply, but not easy to fit, simpler to just buy a replacement actuator head.

 

[CountryFan]

It would be allowing heat to both circuits (whether called by the stats or not).

Yeah, just realised that, doh!

 

[fixitflav]

I have noticed that the pump does sound noisy and is vibrating a bit but this has been going on for a lot longer than when these issues have.

I would start by checking the pump, most likely with a view to replacing. Close the valves, and remove the motor/impeller (4 Allen head bolts). The impellrer might be full of gunge, mine was last time I replaced it.

 

[Harry Bloomfield]

I would start by checking the pump, most likely with a view to replacing. Close the valves, and remove the motor/impeller (4 Allen head bolts). The impellrer might be full of gunge, mine was last time I replaced it.

That could be confirmed by the boiler, running in short cycles, because it is unable to get rid of the heat it is generating.

 

[fixitflav]

That could be confirmed by the boiler, running in short cycles, because it is unable to get rid of the heat it is generating.

That could be what's happenung. OP - can you tell us? You might need to watch and listen to the boiler for a while heat is called.

 

[Harry Bloomfield]

That could be what's happenung. OP - can you tell us? You might need to watch and listen to the boiler for a while heat is called.

It could prove to be, the OP's pipework is choked up with debris, hence the noisy pump, and poor performance, but hopefully not.