Help! Water scorching since pump replaced!

immoral_angeluk

We had a leak in our central heating so CHN came out and replaced the pump which had gone apparently. But every since out hot water has been scorching hot even though we've turned the water thermostat right down to 30 C and it's so hot it's burnt my hand but we can't see why!!!! Any ideas?? The immersion heater isn't on and the thermostat is right down but it's not made any difference! I worried that someone's going to get scalded (we have a nearly 2 yr old) or our gas and electric bills are going to go through the roof!!!
help!

bruce2110

what type of system/boiler is this please...?? ie is it a combi or tanks in the loft for instance??

bruce2110

immoral_angeluk

Well it's not a combi... we have a back boiler behind the fire.. an immersion heater in the airing cupboard and what we can only presume is the water heater above that in a sealed off bit above the immersion.
Does that make sense? lol.

bruce2110

yes it does, thank you for extra info! i think by the sound of it either your boiler temp stat has failed or the thermo stat on the cylinder has broken/failed which is why there is no control on the temp of your hot water as the controls in place are not telling the boiler to shut down once the cylinder has reached tempreture.

this is a job for an heating engineer(not just jobbing plumber type) and you should expect to pay £60 - £100 max including all parts and any labour.

hth!

Bruce2110

immoral_angeluk

bruce2110 wrote:

yes it does, thank you for extra info! i think by the sound of it either your boiler temp stat has failed or the thermo stat on the cylinder has broken/failed which is why there is no control on the temp of your hot water as the controls in place are not telling the boiler to shut down once the cylinder has reached tempreture.

this is a job for an heating engineer(not just jobbing plumber type) and you should expect to pay £60 - £100 max including all parts and any labour.

hth!

Bruce2110

this is why I'm glad we're housing association tenants! lol! We've already had them out 3 times now, first for the pump thing, the 2nd time because the fuse went (because of faulty new pump :rolleyes:), and then a 3rd time because one of the pipes sprung a leak! all of this in the space of 2 weeks! Guess I'll have to call them again tomorrow! I'm so glad we don't have to pay for repairs!

gzed

They may also have by-passed the thermostat during the installation and forgot to put back right up.

matto

Have you turned down a thermostat on the boiler or one on the hot water tank? I'm guessing because you say it says 30 C on it that you have just turned down the hot water tank thermostat. These tend not to work whilst you have you central heating turned on(on older installations).

You need to turn down the one on the boiler. It should be accessible on a back boiler if you look (with a torch) at the very bottom through the gap between the fireplace floor and gas fire. You should be able to see a knob with numbers on it 1-5, or something similar. Turn this down. The bottom part of the fire will most likely pull off (& push back on) to provide better access.

Oh and you do have the immersion off don't you?

gzed

matto wrote:

Have you turned down a thermostat on the boiler or one on the hot water tank?

You need to turn down the one on the boiler.

No I would disagree with that. The thermostat of the boiler controls the water temperature of the central heating (how hot is your radiator). There will be an additional thermostat at the water tank. This is the one causing problem.

eg: my thermostat at the boiler is set a 60 deg C and the one at my water tank is at 40degC. Both are working independently.

gzed

My reply concern the post prior edition. Although i still think the running water thermostat will be located on the tank and not on the boiler.

matto

If there's a two port valve in the control system then the hot water cylinder thermostat will be ineffective if the radiators are on.

The maximum temperature of the water in the radiators and the hot water cylinder is governed by the boiler thermostat.

Have you radiators been any hotter recently?