Hot water tank heats up when we only have the heating on

[nick_cwm]

Hello,

We are having problems with our archaic back boiler heating and ho****er. Before we payout hundreds for a plumbers I thought I would ask on here....

Basically the system is very old, a baxi back boiler.Recently the hot water tank has started to heatup when we only have the heating switched on. It is literally boiling and I suspect will never stop heating up.

We have a glow-worm old skool control timer, the actual timer bit doesnt work and we just use it for the switch to continuous.

Any ideas other that replacing the whole thing. This isnt an option as we rent and my landlord is my sister with no money!

 

[Simon F]

Hi Nick, welcome along.
firstly are you sure this is a new thing???

it all depends on what controls you have and how it is piped up.
probably most back boiler run on gravity for hot water and are set up so that the water is automatically on when the heating is on.
maybe some more description and pictures of controls/pipes would be helpful.

 

[Ermintrude]

Well if it's rented. Tell your landlord. He has to provide you with an economic way of heating the premises and a safe and economic supply of hot potable water.

 

[Whyme]

looks like your sister is obligated to pay for the plumbers which is what is needed, a good look around in person. in the meantime i'd turn the back boiler stat down if you've no control over hot water temp and its scalding. if the hot water doesnt stop getting hotter and hotter i'd ring a plumber sharpish.

 

[nick_cwm]

Thanks for all your responses. The stat on the boiler doesnt seem to work so the water keeps getting hotter and hotter.

I have attached a few pics, it is rented but informally from my sister and for cheap so we are looking for the cheapest way to fix the problem. As the timer was broken I got a honeywell one from ebay. Try to fit it and couldnt, I then paid £50 for a plumber who couldnt even connect it and put the old one back!

I cant remember if the heating has always heated up the tank, maybe it has but not as much as it is now. it must just be boiling away.

One thing that has happened recently is that when you use a hot water tap, no matter which one, it comes through slowly. COuld there be something connected here?

 

[nick_cwm]

Sorry, I forgot to add one more thing. This seems to be happening since the plumber re-wired the timer....

The light of the HW swtich is always one, even when the switch is off. Also there is a constant noise from one of the mechanical valves. I have disconnected the cable that is the brown and blue for the HW to stop the valve going. Hot water still heats up tho.

 

[albatross]

That is an old system. The valves and wiring look like motor open, motor closed valves. You need someone that knows what they are doing with such an old and rare system. It sounds as though it may be wired up wrong but even then there could be an underlying fault. This is not something that can be fixed with a bit of advice over the internet.

 

[Ermintrude]

Just an old s plan at a glance. Probs need new two port. Some ones messed up cyl stat and probs boiled the crap to block drawoffs.

Plumber and renew heating controls. Check DHW drawoffs. Get it sorted
As if it boils over and header is poor some one could get seriously scalded. Little girl burned to death last year by issues similar to yours.

 

[PlumbBobBob]

nick, if you put your location there may be someone from here who could come and sort this out for you

 

[nick_cwm]

Thanks for your reply. we will act on this then. just so i can make suggestions to the plumber.. what is a two port? and you think the cylinder stat is broken? what are draw offs?

 

[nick_cwm]

I live in Abercarn, near Newport South wales. WOuld be nice if we can get it fixed with minimal cost for now. I really think I will try to convince my sister to get a new system....

 

[jonnyswamp]

I'm not too far away from you, just sent you a PM

 

[newcastle phill]

Any update ?

 

[jonnyswamp]

Hasn't contacted me

 

[jonnyswamp]

Finished job yesterday and Erm was pretty much spot on
Couldn't fit the ebay clock the customer bought (second hand) as the casing was cracked open and exposing wiring etc behind, so seeing as two people had both had a go at it, the first thing to do was start from scratch, not that easy when there were 4 browns and an earth going to the BBU and other cables were also the same
So once all were identified and wired back in correctly (with a new clock) the cyl stat was found to be shot, along with the HW two port(motor on, motor off)
These were then renewed and after a swine of a job to refill (lots of air and a very tired original pump) all was good
Boiler stat was also checked as he didn't think it was working (all good)

 

[albatross]

The valves and wiring look like motor open, motor closed valves. It sounds as though it may be wired up wrong but even then there could be an underlying fault.

Ooh look I was right

 

[nick_cwm]

Hi all, thatnks for your collective help. All sorted now and, whilst empty of pocket, please to have it all working again