Vaillant ThermoCompact Boiler issue - no hot water

[M1AK]

Hi all,

Wondering if I could get some help or advice on my problem...

So the setup is as follows:
Vaillant 624e ThermoCompact Boiler
InDirect Coil Hot Water Cylinder in loft
Stuart Turner Monsoon Shower Pump serving shower
Hive V2 Thermostat

Everything has been working fine 'til British Gas came to do a service. Since then there is either no or very luke warm hot water when the hot water is turned on. Heating works perfectly fine. It is also important to note that the hot water pressure is low.

British Gas came out again and checked and said that the thermostat on the hot water cylinder was clicking at 30 degrees and despite the boiler saying 60 degrees when heating, the thermometer only shows approx 35 degrees from tap. So the hot water cylinder was replaced and now clicks to 63 degrees. The boiler works fine but there is still lack of hot water pressure and hot water.

There are no leaks and it seems that the boiler is heating up fine and is holding pressure.
Anyone have any ideas on what could possibly be wrong?

 

[picasso]

I would check that you don't have cold mains water finding its way into the hot water as it sounds like your boiler/cylinder is working ok.

 

[Doggit]

British Gas came out again and checked and said that the thermostat on the hot water cylinder was clicking at 30 degrees and despite the boiler saying 60 degrees when heating, the thermometer only shows approx 35 degrees from tap. So the hot water cylinder was replaced and now clicks to 63 degrees. The boiler works fine but there is still lack of hot water pressure and hot water.

Well if the Hot water at the taps was 35, and the thermostat was clicking at 30 degrees, then that suggests the cylinder stat was working; and if it now clicks at 63 degrees, then it's telling you that there's hot water at around 60 degrees in the cylinder, or it's the new one that's faulty.

If there's no hot water pressure, and no real hot water, then it almost sounds as though he's shut a valve somewhere, and it's not letting the flow through, and it's then cooling down in the pipes.

I'd call BG and ask to speak to a supervisor.

 

[M1AK]

Thanks for the replies.

So I've had bit of success...

I turned the boiler off and on again and it is now reading 61 degrees, roughly the same as the cylinder stat.

I got hot water running again last night and this morning it turned on fine. So I think hot water is ok now.

The only issue now is hot water pressure. It is fine in the shower as I have a shower pump, but its poor on all our mixer taps and I think the cold water pressure is taking over so you can only achieve hot or cold, no warm if in the middle.

They didn't close any taps or valves, just changed the stat.

There are no leaks in the hot water system visible.

Anything else that may be causing this? The HomeCare cover we had doesn't cover the plumbing so they can't help further.

 

[ianmcd]

Just tell BG to sort it, if everything was fine until they came along then why are you even bothering asking questions, just call them and tell them to sort it

 

[M1AK]

Just tell BG to sort it, if everything was fine until they came along then why are you even bothering asking questions, just call them and tell them to sort it

Unfortunately the BG cover doesn't cover it. They came to service the boiler but the stat giving up was coincidental but they still replaced it. The boiler and tank is doing its job now so I'm trying to find out what could cause low pressure other than these too that I can look into.

 

[ianmcd]

well something is not right, if it was working fine before BG serviced it then it should still be working, if not then the service engineer has changed a setting, if you had a problem before the service visit then you should have been honest with the engineer

 

[OvertonPlumber]

"So the hot water cylinder was replaced "

How is the shower pump fed from cylinder from the secondary or a top mounted flange?
Flange can cause a drop in gravity pressure.