Worcester 15/19 Heatslave no HW or CH Water

[Burnerman]

Good morning Kelvin
Top pic - thats the screw that controls the air supply into the burner. It has no bearing on your problem.
Bottom pic - that is indeed the overheat thermostat that needs to be manually reset if its tripped.
I'm still convinced that you have a water flow problem - naturally - and either its air locked or the pump simply isn't functioning properly. Talk about stating the bloomin' obvious.....
I've never come across steam coming out of the bleed valves before - I would have hoped that the boiler would have shut down before that. Presumably the 'stat phials are pushed inside their tube?
Is your new pump the same as the old one, regarding rotation etc? Sorry, don't want to sound patronising!
John

 

[welshcob]

Good morning to you John,

I agree with you in thinking it's a flow problem. When I say it's steam it's more a mix of steam & water, the pump was brand new it's rotation is correct anti-clockwise, the back plate for the pump is correct where you can see the water outlet inside the pump is uppermost, from the 1st set of photo's I uploaded are you able to tell me which pipes should be getting hot after boiler start up.


Thanks for your time, it's very helpful to know that I'm not on my own.

Regards

Kelvin

 

[Burnerman]

Wracking whats left of the remaining brain cell......
When you refilled, did you hold the diverter valve lever to the middle position and hold it there? Did you take the plastic cap off the automatic air vent.....air should purge from there. It could be an idea to actually loosen the AAV if you suspect the thing is corroded up.
The heatslave tank holds about 10 gall of water. When the hot tap is opened, the pump (and burner) starts, and water flows from the heatslave to the domestic heat exchanger - the rectangular thing on the top. Hot water then theoretically comes out of the tap.
I think you have to be air locked, but I know that these boilers have a restrictor just after the flow switch, and a hot water check valve where the pipe enters the heat exchanger. I have no experience of that one though.
John

 

[welshcob]

Hi John,

Today I tried changing the pressure vessel but again no joy, I checked it before fitting & it had been already pressurised to 8.5 psi, I let the boiler fill up very slowly & set the diverter valve right over to the left in the manual position, as the boiler is filling up I can feel air get push out of the AAV so yes I had taken the plastic cap off the automatic air vent, the is no excess water being pushed out of the overflow outside, the one thing I did notice that the 4 pipes on the top of the boiler that go to the heat exchanger the only one that is hot is the one marked "From diverter valve" there is a little heat in the pipe marked "CH flow" but it doesn't go much distance along the pipe, I can feel the 2 half's of the pressure vessel & one side is warmer that the other, John do you think it might be the heat exchanger blocked can I take this off to check it, would you happen to know the part number for a heat exchanger.

Many Thanks again

Kelvin

View media item 38175
View media item 38176

 

[Burnerman]

Well, Kelvin!
Presumably the system was ok before, with just a noisy pump.....?
So - the pump needs to run for both CH and HW.For the CH, if the system has water and the pump is running, the only thing that can stop the circulation is an air lock or the diverter valve, which you can manually control. (Presumably the pump isn't upside down or anything crazy like that). Thats why the CH flow pipe is only warm, because water isn't flowing through it.
For HW, the pump starts and shoves hot water from the heatslave tank into the DHW heat exchanger, where fresh cold water is heated and fed to the taps by mains pressure. Presumably your hot taps are just running cold?
You seem convinced that the new pump is fine. I can't argue with that one!
I think you have an air lock which the pump can't shift. Maybe cracking some of the pipe joints open with the pump running could help?
I haven't fitted a DHW heat exchanger but I believe the part number is 87161429060. I get loads of bits from www.heating-parts.co.uk and they list it as part number 288339. At this stage, I cant see why you need one though, really.
I'm not sure what to suggest next but it sure looks like a pump or air lock issue,as before.
John

 

[welshcob]

Hi John,

I forgot to mention this morning while fitting the pressure vessel I had the powerhead off the diverter valve, I checked the valve for movement & I was easily able to turn it by hand about a 1/4 back & forth, there didn't seem to be any tight spots.

This is all very strange as the boiler has always been ease to work on, 18 months ago I had a extension built, the boiler was moved into it & I done all the plumbing, it started up without a hitch it's been going great in it's new position.

What can I say but thanks again.

Kelvin

 

[welshcob]

Hi John,

Thanks for the heads up on that company you might want to try this company for parts, the same heat exchanger with them is £98 , www.hwos.co.uk/trade & good next day delivery.

Regards

Kelvin

 

[welshcob]

Hi John,

Today I'm going to try taking off the domestic water heat exchanger, the hot water seems to be going to the exchanger, but the pipes coming out are all cold, perhaps there is some crud in it, I'm trying not to buy anything that's not needed, is there any other forum members that would like to offer their views.

John if you are ever down West Wales drop me a line & Ill take you for a ride in my Cobra it has a Chevy V8 engine & it's bloody fast.

Thanks

Kelvin

 

[welshcob]

Hi John,

I got the heat exchanger off there doesn't seem to be any crud in it, there is a one way valve on top of the heat exchanger, as below could it be that this is faulty????? it's position in the boiler is as it is in the photo, the bottom is the front of the boiler, the in & out is marked on the photo's, as you stated you said that it should need changing.


All this great weather, I should be out driving my Cobra, BUGGER!!!!!!!



Regards

Kelvin

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• welshcob
• 1 Oct 2011
• 1

Untitled

• welshcob
• 1 Oct 2011
• 1

 

[welshcob]

Hi Guys,

Is there anyone else out there that can pick up on this thread, I refitted the heat exchanger & it's still the same, there is no hot water getting through the HE when I open the middle bleed valve there seems to be a lot of pressure on the water coming out, I've tried running with the diverter valve in auto & manual with no difference I've also bleed all the rads, CAN ANYONE PLEASE offer any advice I'm at them end of my tether, I don't know what to try next PLEASE HELP.

Living in hope

Kelvin

 

[simond]

Coming in at the end here, I'll add my observations, which are really a summary of the others here.

The boiler is locking out on high temp.
You changed the pump because it was noisy.
The boiler only locks out on high temp, after 7 mins or so when it is started from cool. When hot it locks out almost straightaway.


If the new pump was shagged, it would not allow the DHW heatstore to warm up via the plate heat exchanger. The water simply wouldn't circulate and with 17kW cooking you would get nowhere near 7 mins, more like 7 secs, before the high temp lockout.

Therefore, there has to be an airlock or blockage in the CH side, not necessarily anywhere near the boiler.

I am curious that you changed the pump 'because it was getting noisy'. Noisy pumps are often air filled ones. Had the pump actually died before it was changed or was it just noisy?

I'd look elsewhere in the system for an airlock or blocked non return valve before changing anything else. Running a mains pipe into a drainoff on a rad and letting it run through the drain off in the boiler can cure difficult airlocks.

 

[spraggo]

Hi Guys,

Is there anyone else out there that can pick up on this thread, I refitted the heat exchanger & it's still the same, there is no hot water getting through the HE when I open the middle bleed valve there seems to be a lot of pressure on the water coming out, I've tried running with the diverter valve in auto & manual with no difference I've also bleed all the rads, CAN ANYONE PLEASE offer any advice I'm at them end of my tether, I don't know what to try next PLEASE HELP.

Living in hope

Kelvin

Go to google and type worcester 15 19 heatslave.

Select discontinued oil fired boiler literature-worcester bosch group uk.

Select the heatslave series, RS or CF and down load the Installation and service instructions. The fualt finding section should solve your problem.

Regards

spraggo

 

[Boilerman2]

No heat or Hot Water - boiler fires for 6-7 mins and cuts out on temp
no lets be logical - the diverter valve sends water to the plate HE or the radiators, so regardless of the state of the diverter the water should pump to one or the other or both!, you are getting no heat & no hot water , you assure us you have filled and vented every manual air vent (there are three in total) so
1) have you ensured that the auto air vent is working?
2) is your new pump definately pumping impellor COULD be slipping on the shaft!!

My money is on a fault cirulation pump! logially it can be nothing else!! !

 

[welshcob]

John, Simond & Spraggo,

I think I've found the answer, the NEW circulation pump is faulty, I checked it when I 1st fitted it & is was OK, I just checked it now after burner had kick in & it's not turning, I'm to shattered now to do anymore today so it will be in the morning, fingers crossed.

John, Simond & Spraggo, if any of you 3 are down in West Wales 4 miles from Tenby you can have a free weeks holiday in my caravan.

MANY MANY THANKS to ALL 3 of you.

Kindest Regards

Kelvin

 

[Boilerman2]

Erm ! Who said the new pump could be faulty???