Vaillant 828E Problem

[Noisemaker]

Hi All

I have a vaillant 828E boiler newish. It worked OK until yesterday afternoon. I have incorporated an immersion hot water cylider into heating circuit for the very reason should the boiler be out service for breakdown or service then I can use immersion heator for hot water.

I have fitted a valve in the flow line to stop flow going back to boiler whilst am I using the immersion heator. This valve is opened when boiler supplying hotwater. Another valve is also fitted on outlet side of immersion heater to isolate flow from boiler returning into cylinder.

I was testing the system when the boiler started to deliver hot water for a minute and then going cold. The boiler manual doesn't list this fault.

What is causing problem. I would be grateful for any info that will help me solve this problem. Thanks in advance.

Noiseman

 

[blahblah]

Am I right in thinking you have a hot supply from a cylinder with an immersion heater in it vented to a cold water storage tank, and the hot supply from a combi linked together into one pipe? What type of valves have you used? How operated etc? If the boiler worked for say three years without breakdown, would the water in the cylinder just be sitting there? Never heard of it but won't cry 'foul' without more thought.

 

[Noisemaker]

Am I right in thinking you have a hot supply from a cylinder with an immersion heater in it vented to a cold water storage tank, and the hot supply from a combi linked together into one pipe? What type of valves have you used? How operated etc? If the boiler worked for say three years without breakdown, would the water in the cylinder just be sitting there? Never heard of it but won't cry 'foul' without more thought.

Hi blahblah

Thank you for responding. Yes the immersion is vented to cold water storage. Yes hot supply is linked together into one pipe. I have used a ball valve in (flowline from immersion and boiler) serving bath tub, basin, kitchen sink and the washing machine.

I have also used a gatevalve on the outlet on the immersion cylinder.
As per my posting the immersion cylinder is delivering to all hot points. I had an air lock this morning. I unlocked this fairly easily. Yesterday the boiler started playing up. Oh my other half tells me this hot and cold has been happening for couple of days prior to fitting immersion cylinder. The cylinder was lying idle in my garage for 18 months when the combi boiler was fitted. (Could the problem be my mains pressure is quite high and I live in a hardwater area)

Any help will be appreciated.

Noiseman

 

[corgiman]

why did you fit the cyl on a combi

and what pipes did you use???? ie did you get the boilers flow and return pipes to the cylinder, or did you pie up the hot water to it


Sorry to sound dense but I cannot really understand exactly what you have done??


any chance of a picture

 

[Noisemaker]

why did you fit the cyl on a combi

and what pipes did you use???? ie did you get the boilers flow and return pipes to the cylinder, or did you pie up the hot water to it


Sorry to sound dense but I cannot really understand exactly what you have done??


any chance of a picture

Hi Corgiman

Thanks for your response.

I have incorporated immersion cylinder on a combi to back up hot water should the boiler be out of service for breakdown/service. I can then use two manuel operated valves to switch over from one system to onother giving me hot water.

For some unknown reason to me my boiler fires up and delivers hot water for a minute or so then it goes cold. With this fault occuring soon after I completed the immersion cylinder installation I am now using immersion clylinder for hot water.

The hot water flow is isolated at "Tee" where it joins into pipework feeding my bath, basin, kitchen sink and washing machine. Believe me budd the system works.

I can forward you the schematic drawing if you let me have your e-mail.
Any feedback on the problem with my boiler. Heating side is Okay. Why hot water side has developed this fault. Looking through postings on this forum a number of people have had similar problem (apparantly a common fault with combis). The fault is pointed at diverter valve and flow switch. I am going to have a look at them this afternoon. Should I find anything and able fix the problem I will post on the forum.

Noisemaker

 

[corgiman]

is the heating cycle ok

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[ChrisR]

" Oh my other half tells me this hot and cold has been happening for couple of days prior to fitting immersion cylinder. "

Absolutely nothing to do with your new pipework then, is it!

The water in your cylinder will stagnate though if you don't use it. It will become a serious health hazard, smell disgusting and all the plumbing will need to be flushed by a professional, with chlorine! Perhaps you should install some more stuff so the wc filld from the cylinder, then you'll have a backup if the water supply fails too. You will of course get hot flushes when using the immersion heater, but so what.

Your boiler behaviour might be what you get if the system wasn't cleaned propery when it was installed. Does the boiler come on again after it has gone cold if you leave the tap running. Same on all hot taps? Suppose you open all taps?

And as above, what about the CH?

 

[Noisemaker]

" Oh my other half tells me this hot and cold has been happening for couple of days prior to fitting immersion cylinder. "

Absolutely nothing to do with your new pipework then, is it!

The water in your cylinder will stagnate though if you don't use it. It will become a serious health hazard, smell disgusting and all the plumbing will need to be flushed by a professional, with chlorine! Perhaps you should install some more stuff so the wc filld from the cylinder, then you'll have a backup if the water supply fails too. You will of course get hot flushes when using the immersion heater, but so what.

Your boiler behaviour might be what you get if the system wasn't cleaned propery when it was installed. Does the boiler come on again after it has gone cold if you leave the tap running. Same on all hot taps? Suppose you open all taps?

And as above, what about the CH?

Hi ChrisR

Your are right that the water will stagnate if not used. (a good point mate)I considered this and I plan to run water off atleast once a week. Also I am drawing water from header cistern to feed toilet cistern. (no problem there).

The boiler goes through its sequence fires when any hot tap is opened. It delivers hot water for a minute then goes cold. It's same on all taps. CH is okay.

I am about to embark on the diagnostic mission this morning (if my other half makes me a breakfast first). Its my feeling my mains pressure is too high. I will reduce this and try boiler. If this doesn't work I will look at diverter valve. (Numerous postings here point to diverter valve and flow switch) apparently a common fault with combis (either no hot water or no heating. (A couples scenarious hot water only if heating is on).

I hope you beat me to it with an answer the real cause of this fault. I will however post here whatever happens. Not having hot water is a pain.

Noisemaker

 

[DP]

Noisemaker would suggest you get a heating (proper) engineer in to look at the system. Do not jump to conclusion having read a few posts. By all means take on board what is being said, but in each case follow up with diagnostics. Heating engineers on the forums cannot carry out remote diagnostics, but I would agree with what Chris has to say.

When you say the boiler is oldish, what do you mean by that. Was the boiler fitted new? Was the installation chemically cleansed and inhibited? Is the plumbing plastic? Why have you fitted umpteen valves and not standard motorised valves as suggested in a S or a Y plan? Many questions but expert help is what you probably need.

 

[Noisemaker]

Noisemaker would suggest you get a heating (proper) engineer in to look at the system. Do not jump to conclusion having read a few posts. By all means take on board what is being said, but in each case follow up with diagnostics. Heating engineers on the forums cannot carry out remote diagnostics, but I would agree with what Chris has to say.

When you say the boiler is oldish, what do you mean by that. Was the boiler fitted new? Was the installation chemically cleansed and inhibited? Is the plumbing plastic? Why have you fitted umpteen valves and not standard motorised valves as suggested in a S or a Y plan? Many questions but expert help is what you probably need.

Hi Dp

You guys are great in that you attempt to help. I talked to a old buddy of mine now living in Canada still practicing plumbing and heating there. I explained to him what I had done and what problem I had encountered.

He asked for an hour to study my plan. He got back saying the system cannot work because creation of pressures from two sides i.e from immersion cylinder with the header cistern and the boiler trying to deliver hot water on call. In essence two opposite pressures are fighting each other.

I disconnected immersion cylinder and fired boiler called for hot water . There it was boiler running like it was new. Problem solved.

No buddy the boiler is only 18 months old. The guy who fitted for me was nice chap a professionally qualified engineer but he threw it together and I was there at comissioning. It worked he smiled I smiled I paid him He disappeared. Same night my neighbour complained about hearing horn like sound. It was the boiler sounding at startup.

I had this engineer back. He did something to the air intake muffler. It was OKay. Next the guy disappeared completely in that he took my boiler manuual and fitting instructions with him. Last I heard he headed Ausie way. I have since got new set of manuel and fitting instructions.

What I would to know " is there a back up of some sort" should the boiler fail or is out of service for any reason. Back home in canada the heating is forced air through a furnace and water is heated through a gas fired heater. (Water heaters are hired at a set rate of dollars per month. Should the damn things go wrong you call them out. Usually they respond pretty quick. All the problems are theirs. I had a water replaced my home at midnight outside temperature was -39.

However I am facinated by the small wall hung boilers. Serving both heating and hot water. The furnaces take up lot of room and are ugly. I am planning to take a boiler with me when I go back in about 12 months.

Central heating here is heathier than the forced air system. Okay its fast and volume output is huge but it doesn't suit some.

I am planning to introduce water filled central heating in canada.

Noisemaker

 

[DP]

Send me an email. We will bandy words off forum on what you can or cannot do. I will however say that what have in mind, I have done several times.
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