Vented Indirect System Questions

[nick17]

Hi,

First of all, apologies, I have a really annoying need to understand things in minute detail. Today my Hot Water Cylinder seemingly ran out of adequately heated water after two short showers. The cylinder was heated between 8:30am-9:30am to a temp of 60 degrees. The only use was two short showers and filling a bowl for washing dishes. At 6:30pm I attempted to fill a bath and the water was around 35 degrees. The cylinder is around 117 litres so my assumption is that, simply, it's used up too much hot water and the cold that's replaced it has brought the total temperature of the cylinder water down. Would that be accurate? The other hypothesis (tongue in cheek) is that when I heated the cylinder this morning it was inadequately heated due to the central heating being on at the same time. Could that be likely? It's a vented, indirect system.

 

[ShaunCorbs]

Where was the temperature measured from ?

 

[nick17]

The bath water. I used a thermometer as I was running it because it was for a baby.

 

[ShaunCorbs]

The bath water. I used a thermometer as I was running it because it was for a baby.

would double the time the hot water is on for

 

[nick17]

Is an hour not enough normally or just because the heating is on at the same time. I believe Combis struggle to do both simultaneously (is that right?) but is an indirect vented system going to do it but slowly?

 

[ShaunCorbs]

No not long enough with the heating on aswell

combi boilers will do one or the other will always priorities hot water

 

[John.g]

Is an hour not enough normally or just because the heating is on at the same time. I believe Combis struggle to do both simultaneously (is that right?) but is an indirect vented system going to do it but slowly?

A measured 60C would indicate that you had a tank full of hot water but two short showers is a bit subjective, 2X 5 minute showers at 10 LPM will knock the stuffings out of that 117 litre cylinder.

 

[Roy_66]

Just a silly question. How long is the hot on for in the evening, and is the tank and associated pipework all nicely lagged.

Assume that's not a power shower . . .

Cheers,

Roy (Amateur)