CH + Hot water

orrla

Hi, I am looking for your advice, please.

I've moved recently in to a new flat (1 bed / 1 person) convinced that all was working fine just bit strange - now that it is getting colder outside I am discovering faults. My CH controls are all not working; when I switch it on a boiler heats up water in a tank too (the tank was previously electric but connected to gas now). I had a plumber in to tell me how to use it - he checked all and took a thermostat off the tank and said this would do fine. Now, after about an 1.5 hour water in the tank becomes very hot - I don't use much of it as I have an electric shower and hardly cook so not much washing up to use it on either. I am worried about how heating will work during winter and if it will survive. I don't mind doing some work to this system - it will need to be done one day soon anyway (both boiler and tank are old) - but since I am very busy I would preffer to do it next spring - I am also worried about a mess and time. So, my questions are: should I do it soon and would it be simpler to replace the boiler with combi one or, disconnect the tank from gas, make it electric again? I assume that radiators are ok and do not need to be fiddled with. What would take less time, less mess and cost less? What cost it wold be, roughly?
Thanks for your opinions!

Cardew

Welcome to the forum.

With some older CH systems it was not possible to select Central heating on its own - Hot Water comes on with Central Heating so your system is probably working as designed.

Provided your HW tank is well lagged you will lose very little heat from your Hot water tank; and the heat 'lost' warms up the fabric of the house.

Given that it costs about three times as much to heat hot water with electricity than gas, you would be advised to leave the system as currently installed.

You will never recover the costs of alterations to the system. Removing boiler, Hot water tank and fitting a combi would probably cost a couple of thousand pounds

orrla

Hi

Thanks. But my concern is - having no experience with HW tanks - if the tank will not over-heat? Motor supposing to shut a valve (I hope I am repeating what plumber said correctly) is jammed, so he disconnected it. No control is working besides a thermostat on the boiler (just 1,2,3,4,5,6). I can only turn it on manually. I am scared to use heating for more than 1.5 hours... How safe it all is?

Cardew

orrla wrote: »

Hi

Thanks. But my concern is - having no experience with HW tanks - if the tank will not over-heat? Motor supposing to shut a valve (I hope I am repeating what plumber said correctly) is jammed, so he disconnected it. No control is working besides a thermostat on the boiler (just 1,2,3,4,5,6). I can only turn it on manually. I am scared to use heating for more than 1.5 hours... How safe it all is?

The control on the boiler sets the temperature of the water produced by the boiler - usually between about 45C and 80C.

So the water in your tank will not get above whatever you set on the boiler.

Most systems have a thermostat on the tank that controls the temperature of the water(from the boiler not the immersion heater) independantly from the temperature in the CH system. It seems that your plumber took this thermostat off.

From what you say there is a 3 way valve that diverts water from the boiler to heating, hot water tank, or both.

I can't understand why a plumber wouldn't replace the valve and not remove the thermostat???

Is he trying to get the job to replace the CH system????

There are some helpful plumbers that come on this site, who know far more than I, let us hope they will comment.

P.S.
The system is safe - but don't have your boiler setting above 3 or 4 or the water in your tank will be scalding.

macman

I suggest you get in a properly qualified plumber to fix the 3 port valve and reconnect the 'stat.

orrla

Thanks Guys!

Yes, new plumber arranged for Thursday - let's see what he'll say. I don't feel safe with the way all this is now...

orrla

Hi again!

New plumber's verdict was:

- it is a 2 way valve system - each new motor's cost ca £70. Boiler (Baxi) unsafe - replacement costs to be given early next week - when replacing must drill new hole through a wall for a flue.
- that a cost of fixing combi boiler would be comparable to costs of the above.

Is he having me on? What's your opinion, please!

Thanks!

orrla

He, he, he. Only £2218.80 at it will work, says the last one. I love this 80p best!

Where will I find a good, honest plumber who will fix this and won't take me for a cash machine? Any suggestions? Thanks!