Unvented system - hot water not very hot.

[teecee90]

Okay, well I think I'll get the thermostats replaced. It's a pretty simple system really and I can't see what else could be the problem.

 

[townfanjon]

Okay, well I think I'll get the thermostats replaced. It's a pretty simple system really and I can't see what else could be the problem.

Good look on locating the stats , sorry you may struggle , but good luck .
I havnt read everything above but has there been water running through the tundish ? , did the engineer go into the loft ?

 

[teecee90]

Seems to be plenty of those thermostats available online - S6211

There is no leakage from the TP valve and the expansion vessel is properly pressurised

 

[Best]

Seems to be plenty of those thermostats available online - S6211

There is no leakage from the TP valve and the expansion vessel is properly pressurised

How do you know the expansion vessel is properly pressurised?
The engineers you said yourself you had no faith in them, plus you have faults unrectified

 

[Best]

Strange the engineer wrote 1200mm D1 length, but then didn't correct it or note it on the Observations part of form.

 

[teecee90]

How do you know the expansion vessel is properly pressurised?
The engineers you said yourself you had no faith in them, plus you have faults unrectified

Because I've checked it myself.

Must admit I don't understand the D1 issue - can anyone explain? As far as I know nothing has been changed since the property was built, other than replacement of the motorised valves, anode & TP valve a couple of years ago.

 

[ShaunCorbs]

Because I've checked it myself.

Must admit I don't understand the D1 issue - can anyone explain? As far as I know nothing has been changed since the property was built, other than replacement of the motorised valves, anode & TP valve a couple of years ago.

From the safety valve the black tundish needs to be within 600mm

So it wasn't right from day one

 

[teecee90]

I might be wrong, but looking back over previous versions of the regulations, at the time the house was built it seems that the requirements was for the tundish to be a maximum of 500mm from the valve measured horizontally and for a minimum 300mm fall after the tundish. There is no mention of a maximum pipe length between the valve and the tundish, although later regs set this at 600mm. So, it wouldn't meet current regs but was probably okay at the time it was built.

https://i.*********/k8vo0Ri.png

 

[Best]

It was previously 500mm D1 maximum length to tundish, but recent years was changed to 600mm.
The instructions and regulations description and drawings can be a bit confusing I must admit.

 

[townfanjon]

Because I've checked it myself.

.

I am intrigued, how have you done that ?