Worcester Greenstar 25Si DHW Problem....(Combi)

[lummocks]

Hi, just after a few ideas before I call out the dreaded plumber or if it is something that I can change myself?

My boiler seems to have done this now and then since installation but very infrequently now it is doing it almost if not every time there is a demand for hot water.

When you turn on the tap (hot or shower normally set to v.hot!) the water always seemed to take a long time to get hot (boiler not set in eco mode) i'm unsure if this is relevent to below problem.

Problem:

Now when you turn the tap or shower on it never gets hot and stays luke warm unless you turn the tap down slightly to 1/4 turn then it comes out so hot you can't even touch it (hot water dial on boiler set to 5)

I've just been into the loft where the boiler is situated and asked my other half to operate the tap on the bath in various states as mentioned above, the burner lights quickly in all cases but when the tap is on full you can hear water bubbling through parts of the boiler (i've not removed the cover so have no idea where about this is coming from)

Hope someone could shed some light I hate cold showers!

Doesn't seem to have any problems with CH.

Thanks in advance

 

[twgas]

Bubbling in boiler is often due to a blocked condense drain, but if that is the case I'm surprised it hasn't locked out.
Does the CH flow get hot when you run the hot tap?

 

[lummocks]

Hiya mate, just been in the loft and had a quick look, bearing in mind CH has been on flow pipe hot to start with...ran the tap full whack whilst feeling the pipes DHW pipe red hot for a second then luke warm CH FLOW remained hot. Looked at the condensate trap (from underneath) and it appears only to be half full which I assume is correct.

Thanks for your reply.

 

[twgas]

The CH flow pipe will not cool down terribly quickly, you really need to let the heating cool down, then see if it gets hot while the hot tap is running.
There would normally be some water in the condense trap, but if the outlet is partially blocked it may build up and after a while cause the bubbling, before slowly draining and then operating, apparently, normally for a while.

 

[lummocks]

Will have a better look tomorrow when everyone is out the house, thanks very much for your help thus far