HELP REQUIRED !! NO HOT WATER

[achurch]

Hello All

Ok I woke up 2 weeks ago with no hot water, central heating was fine so guessed it was the 3 port valve.

Contacted my insurance company Home Serve and informed them of my observations, they sent a man round on a Sunday but he could only state the obvious and didn't have the part on board but one was ordered,the next day another man turns up with a 2 port valve lol.
Finally got the honeywell 3 port fitted only to find no heating downstairs, so they then fitted a new grundfos pump and all was great.

Within 2 days I had no hot water again, central heating was fine I checked the inlets to the 3pv hot was coming from the pump and to the central heating but hot water was not being diverted through the copper storage tank, I turned the system on and off at the isolation switch and the motorised valve did what it was supposed to do and started pumping hot water through the copper tank, I did hear a strange gurgling noise but then within a few minutes I could feel hot water went through the cylinder at the inlet and outlet, I rang the company but sods law all was working fine when the fitter came.
Then the next day when at shower time that evening after heating and hot water had been running a couple of hours, same scenario after turning the whole thing off and back on it worked.

Any ideas ? as I look like im pulling there leg when the guy turns up, my system had been fine for the last two years.

Thanks Al

 

[Phill Peck]

Stop using homeswerve and call a descent engineer?

 

[gigz]

Have you or they vented the coil ?

 

[Tay7]

Airlock on the coil.

 

[achurch]

Hello

Thanks for the replies, im not sure if they did vent the coil or not, I know they did not drain the system down to do the work, the pump has isolation valves top n bottom and they isolated and drained enough off from within the airing cupboard to be able to fit the 3 port valve and pump.
Bit of a mystery, but it was working fine before and should be now its had 2 new parts.

Thanks

 

[stem]

I woke up 2 weeks ago with no hot water, central heating was fine so guessed it was the 3 port valve.

For future reference, if a 3 port valve motor fails, the valve will default to the hot water only position, so the hot water will come on, but the central heating won't. Not the other way around.

 

[Agile]

But that's only if the HW and CH have been connected to the correct ports on the valve!

Also only if the failure is due to the motor winding being open circuit but still free to turn.

The motors can seize up and jam the valve in any position.

The valve body can also seize up and jam in any position.

Tony

 

[stem]

I was pointing out to the OP that they shouldn't have assumed that the valve was faulty based on the symptoms given.

I have never come across one that is both wired and plumbed in the wrong way around, which it would have to be to work properly. That would mean utilising the heating not required signal from the heating control of the programmer, and also the room thermostat satisfied signal. Yes I've seen them plumbed in the wrong way around after replacement, but they never worked properly from the start.

Agreed, it is possible for valves to jam, I can't remember the last time I saw one though, so I would reckon 95% of failures relate to the motor or the microswitch(es) and even if the valve was jammed, it should have been an easy spot for the engineer.

 

[achurch]

Thanks again for help so this is the scenario woke up this morning again central heating fine all rads are hot and I had hot water as I restarted system last night.

Its 8.40am and hot water was supposed to have been running for last hour and half but bottom feed from copper cylinder is cold.
Both the CH and hot water have now gone off via the timer 8.30am, I press + 1 Hr on the hot water side on the programmer and bang its starts working immediate hot water starts flowing through the copper cylinder.
It seems to be that its not working in conjunction with the central heating and timer ?

I will get them back in but moment I do they press individual and it works ok ? driving me nuts now..

 

[oldbuffer]

As above, I'd suspect a lot of air in the system. Possibly travelling round, then getting locked into the hot water cylinder coil from time to time. Bleed all air out of system, including coil. System off, start at lowest floor, bleed radiators, bleed cylinder coil. Start system, run for 30 minutes, repeat until quiet.

Incidentally, you mention the "bottom feed from copper cylinder". The hot water comes from the top. The bottom inlet (not coil) is the cold water going in and should always be cold.

 

[75pete]

And as a side note, a few years back, our 3port failed over Xmas! So, it failed but still allowing the boiler to heat the hot water cylinder. With no chance of getting the part for the failed valve I moved the manual leaver to the open and locked it in, then adjusted the balance valve on the hot water return ( almost shut). This did the trick of keeping the heating on and no need to mess with the hot water tank stat.

 

[stem]

Both the CH and hot water have now gone off via the timer 8.30am, I press + 1 Hr on the hot water side on the programmer and bang its starts working immediate hot water starts flowing through the copper cylinder.

Hmm... I think this may depend upon the relevance of the 'bang' to the programmer. If there is a loose connection, or the switching relay inside the programmer is worn or weak, then the bang may make the contact, and the programmer could be your problem. If you are able to carry out basic testing and use a multimeter safely, it's fairly easy to check at the cylinder thermostat that it is receiving the correct hot water control signals from the programmer.

On the other hand, if the programmer is working, the symptoms could still indicate that there is air present in the system. When the heating and hot water are both on, the flow from the boiler is split and shared between both, but when you turn on the hot water only, the full flow is directed to the hot water cylinder and may have sufficient force to overcome the air.

 

[achurch]

Thanks all for your help but its still not fixed here is what has happened so far, this has been going on since November 2015.

1)First of all I couldn't get no hot water central when my heating was fine, A guy came and fitted a new 3 port valve.

2)Few days later same thing no hot water in the morning so another guy came and said its the pump so he replaced the pump.

3)Again a day or so later no hot water, they sent another guy out who said its a faulty new pump, so he replaced it.

In the mean time Ive been turning the heating off on the timer and by pressing + 1 hour when we needed hot water I get hot water,it seems that I can only get hot water if central heating is turned off, but the 3 port valve is ok ?.

4) But obviously this is not right so I ring Homeserve, they send a senior guy out who tells me there was a wire loose and says its ok now, but it wasn't right and the fitter says the problem was staring him right in the face and it was the cylinder stat all along.

5) The same engineer comes back fits the new cylinder stat and says hopefully all OK now.

6) But with all the above its still not right any ideas what else could it possibly be ? my heating and hot water was fine before the initial fault.

My Heating is OK, but if I leave programmer to operate both even with the red light on I only get heating no hot water.
I manually turn off the central heating via the programmer and hit button on programmer for hot water and I get hot water flowing through cylinder heating it.

Any help appreciated

 

[75pete]

Good old homesserve, looks like there be back again.

 

[Mikefromlondon]

My guess would be that since all these guys didn't have a clue as to what was wrong initially, they changed 2 pumps! changed 3 way port valve, it probably wasn't the 3 port valve, but he changed it thinking it may be, a valve would remain in one position if the control signal wasn't reaching it, and so he changed the 3 port valve and didn't find the original fault, and during his diagnostic work he probably fiddled around with connections in various places and disturbed some other connections, he most probably knocked a wire off somewhere or found a wire lose and removed it without noticing where it came from and then reconnected it to a wrong terminal, not unusual for those who have no clue what they are doing and make guesses.

It may also be possible that your timer may have given up the ghost, since it is this item that tends to be used more, as you slide buttons or push buttons, a lose connection somewhere, a bad switching, so it may be it is your timer that needs looking into, the +1 hour button works, but normal CH+HW doesn't so it is from this switch that your 3 port valve is controlled. It may also be worth checking wiring all the way for correct termination and tightness of screws.