water heater

please don't shout at me if this has already been answered as I did search but couldnt find the same issue on here. For the first time ever our water heater seems to be behaving a little strangely. I'm normally in charge of pulling all the water through the system on site but this time the OH did it, Due to lack of experience he managed to leave a fair bit of air in the pipes the first time round and so had the usual manic spitting of hot water when i first turned the taps on. Once this had settled down we noticed that the water was nowhere near its usual temperature even a day or so later and would have "sporadic" moments where the water would run scalding then ice cold (only hot tap on at this point. Just wondering if anyone could shed any light on this as its not something that's happened before. I tried the reset button on the heater but it wouldn't push in so figure it hadn't tripped out. any ideas greatfully appreciated

Neil

looks like its a mystery to everyone else to then

Neil,
Was this on gas or electric?

Paulmold wrote:Neil,
Was this on gas or electric?

On electric Paul, its all very strange, would run for few seconds scalding hot, then ice cold then luke warm then cold again then scalding but at this point no air in the system as all pulled through. I cant see how when only the hot tap was on it wouldn't be as hot as normal

Hi there,

Air-locked water heaters can do funny things!

The "hot - luke warm - cold" cycle seems to indicate that only a bit of the reservoir is being heated which in turn indicates an air-locked system; as reinforced by the "spitting".

Air can only get into the system if:

o It hasn't been removed since the system was last drained. (It can take a long time to clear a system if there are any loops and droops in the pipework.)

o It is getting into the system upstream of the pump due to low water level, or "sloshing" when on the move and pump is still on, or there is a crack in the filter or the inlet piping.

o It is getting into the system downstream of the pump. (Very rare as almost all air ingress will be replaced by a water leak when the pump switches on. However, if the heater is switched off at the same time as the pump then there is a chance that the water cooling and contracting in the heater sucks air into the system via the pressure relief valve.)

Otherwise, it is a mystery.

Hope this helps.

Best regards,

Dutto wrote:Hi there,

Air-locked water heaters can do funny things!

The "hot - luke warm - cold" cycle seems to indicate that only a bit of the reservoir is being heated which in turn indicates an air-locked system; as reinforced by the "spitting".

Air can only get into the system if:

o It hasn't been removed since the system was last drained. (It can take a long time to clear a system if there are any loops and droops in the pipework.)

o It is getting into the system upstream of the pump due to low water level, or "sloshing" when on the move and pump is still on, or there is a crack in the filter or the inlet piping.

o It is getting into the system downstream of the pump. (Very rare as almost all air ingress will be replaced by a water leak when the pump switches on. However, if the heater is switched off at the same time as the pump then there is a chance that the water cooling and contracting in the heater sucks air into the system via the pressure relief valve.)

Otherwise, it is a mystery.

Hope this helps.

Best regards,

I'm hoping its just because the OH didn't pull through the water properly initially so fingers crossed all will be OK next time. It was the "why is some water boiling and some freezing when from the same tank" bit I couldn't get my head round but that would makje sense if there is still air in there somewhere lol

Harper22 wrote: .........................

I'm hoping its just because the OH didn't pull through the water properly initially so fingers crossed all will be OK next time. ............

Hi there,

I really don't know why you even asked the question if you already had someone to blame!

All I can say is "Best of luck with that strategy!"; it has never worked for me though!

Best regards,

Dutto wrote:

Harper22 wrote: .........................

I'm hoping its just because the OH didn't pull through the water properly initially so fingers crossed all will be OK next time. ............

Hi there,

I really don't know why you even asked the question if you already had someone to blame!

All I can say is "Best of luck with that strategy!"; it has never worked for me though!

Best regards,

purely because i pulled it through again afterwards (or thought I had lol)

Have you tried the little bleed screw at the top of the heater outside in the grill. Be careful as they can get brittle, just twist slowly one way and air will come out.

Hope this helps.

Best regards, Mike

Flying High wrote:Have you tried the little bleed screw at the top of the heater outside in the grill. Be careful as they can get brittle, just twist slowly one way and air will come out.

Hope this helps.

Best regards, Mike

Oooh yes the bleed screw is my friend already Use if for draining the system faster too, thank you for the suggestion tho