Long suffering hot water issue with worcester greenstar HE Boiler

[The Rig]

Hi Guys n Gals,
Hope all are well.

My mum is in a council owned house,but we dont seem to be getting any closer to a fix despite about 7 engineers coming out.

She has lived in the house 4 yrs, same boiler, no alterations

About 4 mths ago she noticed the hot water started to become intermittant with heat, she would turn the tap on, it would be hot, then go col, then come warm again then cool off then after some time would sustain heat

engineer came out, pressure was blamed, but reducing the flow into the boiler didnt fix anything

next engineer same diagnoses, still no fix, live with it, not a great fix as she is on a water meter and wastes alot of water

i notice she was on the instant hot setting (where it fires up the boiler every 10 mins or so to give "instant" hot water, this clearly doesnt happen, so i changed the setting to be hot only when drawn, this worked for a few days but the problem came back, takes ages to get hot, even if on a slow draw from the tap.

Anyhoo, we noticed that with the central heating on, its ALOT ALOT ALOT worse LOL, if we turn the central heating off, its alot better, still not great, but gets warmer sooner

After i was present on an engineer visit and telling him i`m not being fobbed off with pressure, he changed the heat exchanger, this did nothing to cure the fault.

The bath tap is the worst, the sink and the kitchen taps get hotter quicker, but the bathroom tap is luke warm at best when at its hottest, i had a look under the bath and the pipe is the bigger 22mm not the 15mm, but as i said earlier, it used to be just as hot as the sinks taps

So, any thoughts ?

appreciate any adive

Thanks

 

[LeadByExample]

Hi The Rig,

I can't give you any technical advice, however, I found sometimes it helps if you call the manufacturer. It could be a known issue and give you advice on what to do.

Regards

 

[diamondgas]

Hi The Rig ... My best advice would be to turn back the hot water flow on the bath so that it is coming out slower. This time of year most Combi boilers will be struggling to supply hot water under maximum water flow load If you reduce the flow through the boiler it should pick up more heat for the taps

 

[mountainman]

My best guess is that the diverter valve is stuck or not fully closing the central heating circuit when hot water is demanded.
MM

 

[The Rig]

cheers guys

Diamond gas, this is what she does at the minute but it still doesnt work, i take it you mean, only turn the tap on at a low setting ? if she does this, the boiler either doesnt pickup the flow and doesnt ignite or if it does ignite the water is luke warm/goes cold etc

mountainman, is this a job i could do, i`m a car mechanic LOL or is it tucked inw ith the gas circuit ?

(if the next visit results in a dead end again)

cheers

 

[stevetheplumber]

it will be either the three way not moving as it should or a blocked heat plate exchanger if it was this they cyhanged then the threeway for definate

 

[mountainman]

Diverter repair or change is nowt to do with gas line.
Look up the manufacturers instructions and you will see how to change the unit.
Dunno if you could repair it tho any more than I could rebuild a vehicle fuel injector pump.

Good hunting!
MM

 

[zzzjim]

If the water pressure keeps varying ,this can confuse things , as flow you set keeps changing !

 

[mountainman]

If the water pressure keeps varying ,this can confuse things , as flow you set keeps changing !

Sorry mate but you don't know what your talking about, either be constructive or shut up!

 

[armourer]

Sorry mate but you don't know what your talking about, either be constructive or shut up!

Totally uncalled for mate.
I think what he meant was varying flow rates do have an effect on temperature at the tap. (reduce the flow on a tap and it gets hotter).
I know it shouldn't happen like this as the boiler should modulate, but it does.

Other than that I agree with you MM sounds like the diverter could be letting by into the CH circuit but its not something the op could do as it would be classified as work and he would have to be GSR.

 

[mountainman]

Totally uncalled for mate.
I think what he meant was varying flow rates do have an effect on temperature at the tap. (reduce the flow on a tap and it gets hotter).
I know it shouldn't happen like this as the boiler should modulate, but it does.

Other than that I agree with you MM sounds like the diverter could be letting by into the CH circuit but its not something the op could do as it would be classified as work and he would have to be GSR.

I may have been uncharitable with my comment but speculating on fluctuating water flow is pointless as it only serves to confuse the issue.

Realistically the only way to be sure is for an experienced engineer to check the boiler. In my experience tho the diverted valve is a common suspect.
MM

 

[The Rig]

Cheers for the input guys.

I`ll get my mum to mention the divertor valve, i know she shouldnt have to but the guys that come out just seem to want to blame the flow/pressure into the boiler and thats it.

If the boiler cant cope with the pressure then to me, somethings at fault,simple as,as said above, the boiler should compensate for this pressure or that pressure etc, but they seem to just say, live with it, its an old boiler yada yada, i guess being a council paid bill they either dont have the budget to fix it or i dont know why they cant diagnose the fault properly ???

cheers again

 

[zzzjim]

...... uncharitable... confuse the issue .... MM

Apologies for confusing the issue , was hoping to give user some clues to look out for ,Since he is technically minded !

Let's be short , accurate & Safe .

 

[The Rig]

If the divertor valve is faulty, does that mean,when the hot water is run, its bypassing into the CH circuit,so 1 of the rads might warm up ?

cheers

 

[steveh]

I've got exact same problem. worcester came out and agreed there was a problem. he then said the circuit board was faulty, the potentionometer, I suspected he was wrong but went with it as he was the expert. after he said it was fixed, I checked and said it was the same still broke, he the boiler only raises temp 40 deg above cold temp and the ground was very cold and that was the best we could expect. I'm well miffed

 

[pierrot]

I had one of these yesterday doing exactly this. The diverter valve was stuck and not fully opening. A new diverter valve was ordered.

 

[steveh]

I had one of these yesterday doing exactly this. The diverter valve was stuck and not fully opening. A new diverter valve was ordered.

I'm not very up on boilers. would this stop hot water in the taps completly when the heating isn't on?

 

[Dotty]

As the dv on a wb is inside a sealed case it is not a diy repair as opening the case is a job that may only be performed by gsr's.

You need a gsr in to look at your boiler. We cannot and will not give advice on the installation or repair of boilers for your own safety.

Please go to Gas Safe Register | Ensure your gas engineer is registered. or post a thread in the 'I'm looking for a plumber / gas engineer' section of these forums remembering to include your location. [DLMURL="http://www.ukplumbersforums.co.uk/im-looking-plumber-gas-engineer/"]I'm looking for a Plumber or Gas Engineer[/DLMURL]

If you are gsr please increase your post count to 10+ then send a private message to either Gas man or Redsaw who will then check you and then give you access to the gsr private forum.

Thank you.

http://www.ukplumbersforums.co.uk/central-heating-forum/42241-notice-gas-safety-related-advice.html