Worchester Bosch E9 Error - It's not the boiler !

[Roger Welton]

What buckley says, had a house that was sectioned off into flats each with there own combi's fitted with the exception of the ground floor which retained the existing boiler (40CDi) it was firing winding itself up then shutting off (up to temp) very quickly, dropped the max firing rate down (explained in the CDi engineers booklet off worcester site) and the job was a orange root vegtable

 

[stoker122]

The pump looks like it is pulling on the vent probably on start up.
It may be not pulling as hard just with hot water on due to higher resistance.
It could well be worth swapping the feed and expansion so the pump pulls on the cold feed instead.

 

[MichaelwGroves]

I'm thinking about lineing all my wet jobs up so I only need to drain system once.

Jobs so far;
Swap Feed & Expansion pipes. The Diagram now shows exact placement,is there a preferred point to tap off?
Replace 3 Port Valve for bigger. What would you recommend.

I'm thinking if I need to make the vent changes, should I consider converting to an un-vented system. Any benefits on one Vs the other?

I also have dry jobs, I will down rate the boiler and see how this goes, along with checking return temperature.

 

[Roger Welton]

I'd use 2 x 2 ports instead of a 3 port,

 

[diamondgas]

Is the vent before the pump automatic or manual? If auto that could be where you're drawing in air! Just a thought

 

[MichaelwGroves]

Is the vent before the pump automatic or manual? If auto that could be where you're drawing in air! Just a thought

Manual, thumb screw.

 

[MichaelwGroves]

Looked at this on Saturday, gave it a lot of thought. Clearly Vent is in wrong place and this muct be where airs is coming from, but this is just pushed to the Bathroom radiator where it coolects. It can't get to th boiler. So bad installation by origional plumber but can't be why boiler is erroring. Also 3 way valve, yep agree too small for boiler on max, but if this were the problem I would get problems with radiators not gettinmg not enough. So would be a good upgrade but probably not causing bolier to error. It would just act like sevetral TRV's backing off.

So last idea is down rate the boiler as it's heating up too quickly. Okay, the only time the boiler errors is on start up, once it gets going its fine. So I down rated central heating to 27kW.
Well since then it's been fine, no problems at all. I have left the hot water at 40kW. The radiators are not as hot as they were and the house is on the edge of just being warm enough, so I might tweek to 30kW at the weekend if it behaves itself.
So my advise to anyone who gets an E9 error is down rate it as your very first jobas it only takes 2 minutes.

Thanks for all the advice guys

 

[Roger Welton]

So it must be stuggling to flow the heat away as it ramps up the load on start up.

 

[MichaelwGroves]

That's a good way of looking at it, so if I removed the restriction by way of the 3 port valve, this might also solve it?

2 port valves was recommended, but to keep the job simple can I get a larger 3 way valve that will allow 40kW of flow ?

 

[Roger Welton]

I'd be looking at 2 ports, easier to wire and fault find, plus can flow more heat.

 

[MichaelwGroves]

What models would you recommend, all my pipe work is 22mm, so I would look to replace 3 way with 22mm T, striaght into 2 port valves ?

 

[Roger Welton]

Yup, I prefer honeywell valves personally.

 

[MichaelwGroves]

Would I get a full 22mm flow from Honeywell V4043, not sure on difference for "B" and "H". or would I need 28mm valve to get full flow?

 

[Roger Welton]

From Honeywell training manual

 

[MichaelwGroves]

That's mad, why does Worchester Bosch only come off the boiler in 22mm ?

 

[Roger Welton]

Cost, that's all

 

[vern]

That's mad, why does Worchester Bosch only come off the boiler in 22mm ?

Because in WB lab tests they found you can have upto 1m of 22 mm straight off the boiler before increasing to 28 mm, this has virtually no effect on heat capacity.....this keeps their costs down too! As they send same pipes as 30 kw version!

I would run 28 mm primary's, then fit 2 x 28 mm zones valves, with 22 mm honeywell ABV, then convert to sealed system, job done.....

Micheal you cannot have your heating set on 27 kw and hot water on 40 kw on the 40 cdi, so if you have adjusted to 27 kw, the hot water is set to this also!

 

[MichaelwGroves]

Sorry, don't mean to be argumentative but...........

I don't see how 28mm will give better flow if boiler is only 22mm. But, I can see upgrading pipe at valve to 28mm to get full 22mm through valve.

snip from Manuel, "Even if the heating output is limited, the full rated heat output remains available for hot water"
1.a is setting for CH, 1.b is setting for Hot Water.

What are the advantages/disadvantages sealed over vented?


What's the advantages/disadvanteges sealed over vented?

 

[vern]

Sorry, don't mean to be argumentative but...........

I don't see how 28mm will give better flow if boiler is only 22mm. But, I can see upgrading pipe at valve to 28mm to get full 22mm through valve.

snip from Manuel, "Even if the heating output is limited, the full rated heat output remains available for hot water"
1.a is setting for CH, 1.b is setting for Hot Water.

What are the advantages/disadvantages sealed over vented?



What's the advantages/disadvanteges sealed over vented?

Trust me on the pipe, it acts as a buffer, just like the outlet of a gas meter is only 22 mm, but is often increased to 28 or even 35 mm on some installs.....

the 1a and 1b rule above is only for the combi boiler version not heat only like you have, how do you think the boiler knows wether it is in hot water only or ch mode? It does'nt it has a common switched live sorry you are on 27 kw for both.

loads of advantages foe sealed system google it or search on here and save my finger it has been covered many times!

 

[buckley plumb]

View attachment 11060

From Honeywell training manual

have you got that manual on pdf mate

 

[gpbeck]

Total system resistance is the sum of individual resistances in series. So you can compensate for high resistance somewhere (e.g. boiler) by lower resistances elsewhere.

 

[MichaelwGroves]

I get it now, coming straight out of the boiler in 22mm will have similar resistance as going round a 90 degre bend in 28mm. I have some further upgrades planned, so will look to upgrade pipe and valves at the same time.

 

[vern]

I get it now, coming straight out of the boiler in 22mm will have similar resistance as going round a 90 degre bend in 28mm. I have some further upgrades planned, so will look to upgrade pipe and valves at the same time.

Good gleen as much info as you can, remember we do this for a living :sunny:

 

[Roger Welton]

have you got that manual on pdf mate

I don't I'm afraid, paper only.

 

[MichaelwGroves]

I hate to admit I am wrong, but Vern I reckon you were right about the boiler as well. Obviuos when you think about that one
So do I assume the hot water setting has no effect on my boiler, or should I set this the same?

Thanks