Hot Water storage tank not heating up

[Fast_Muchly]

Hi Folks ,

Recently we have had to have a new cylinder in the boiler its a worcester bosch as it kept losing pressure and a new pressure release valve , i would also say around 12 to maybe 24 months we had both valves replaced on the pipes that lead to the heating and the hot water storage tank to allow water to flow when the system is turned on .

So i come in yesterday and wife says no hot water !! .

Sure enough the storage tank is freezing , i check the centaur control panel and boost the hot water for an hour the boiler doesnt come on at all and the storage tank is cold as ice on all the pipes leading it from it as well . I turn it all off and turn it back on again still no luck .

I then think its got to be the thermostat on the boiler its been on there for years . It does look a bit discoloured on the plastic round the base where it actually touches the tank .But i turned the thermostat and it still hasnt turned the boiler on and yes it was at around 70 degrees not 0 .
When the thermostat turns all the way off and back on again it does click i would say around the 35 degrees mark but poss less .

Because the thermostat clicks does that mean that its 100% o.k as this is the simplest thing for me to change myself for £15 without calling the plumber in . But i dont want to waste even £15 if the click means its o.k .

If it isnt the thermostat on the boiler am i right in thinking that it has to be one of the main valves on the pipework even though they are fairly new , will be irritated if its one of those they dont seem to last 5 mins which ever brand you have .

One more thing with those valves is i thought the boiler had to actually switch on and fire up to send the electronic message for those valves to open or am i wrong on that as the boiler isnt coming on .

p.s Tested the boiler with the CH side and it works fine .

 

[Harry Bloomfield]

From your description, the tank thermostat clicking sounds fine and if the boiler fires for central heating, the boiler seems fine. Your most likely problem is the hot water valve which is sticking. The way it works is that the thermostat powers the valve to move to open, once open, the valve then powers the boiler and pump.

Try tapping the valve, with the stat set to max - it may free it.

 

[Fast_Muchly]

From your description, the tank thermostat clicking sounds fine and if the boiler fires for central heating, the boiler seems fine. Your most likely problem is the hot water valve which is sticking. The way it works is that the thermostat powers the valve to move to open, once open, the valve then powers the boiler and pump.

Try tapping the valve, with the stat set to max - it may free it.

Thanks for that , will try this later tonight only prob is i dont know which valve is the hot water one but will switch the heating on and see which one opens for that , then i know its the other one lol .

Can i ask plz because all the time we have had this system these valves are a REAL PAIN IN THE ARSE , i know they do some work but jesus there forever packing up and so many issues with them i once took it off and kept the valve perm open with some pliers one winter ( i know not a good idea but so fed up with them ) .

In peoples opinions which is the best one plz ? .

Are there known bad ones to steer away from in the trade .

 

[terryplumb]

Is there an electric immersion heater fitted in the hot water cylinder ,that you can use to give you hot water ,until you sort out the problem ?

 

[Hugh Jaleak]

Honeywell Valves are reputedly the best. Avoid Sunvic.

 

[Fast_Muchly]

Hi Folks
Update .

Yes we have hot water switched immersion on thx terryplumb already had that on .

Right after turning stat up on boiler to 90 and running some hot water out of tank and also making sure control panel was calling for hot water i gave it another try . The result after a little tap with a hammer on casing to release anything if it was stuck has not worked at all . A thing i did notice as it was quite warm on top of the valve and hot water wasnt being called for as i had switched the HW and CH off .

What i have tried to do now is switch the immersion off as im pretty sure its more pricy to run than the gas and move the manual switch on the back of the valve/solenoid to MANUAL .......but here is the interesting bit the metal lever is loose there is no resistance like your moving it against a spring its just to easy to move it back and forth in the slot . I have tried the CH valve/solenoid for comparison and that is perfect some resistance like your moving a spring and it stays in manual after you push it up at the end but the hot water valve lever is just not operating the same .

From this im assuming its shot it and we need the plumber can i ask what we should be paying for this type of repair we are in the midlands not london lol im guessing around £80 ......£50 for the part and £30 for fitting . Its so annoying as i had both these change last year on the 4th of july and its lasted just over 12 months absolutley shocking .

I wouldnt mind if i could do it myself , i have done in the past but the ones that are on now seem different ( plumber did it ) the one i did i could literally just lift it off the pipework but its about 10 years ago maybe more . These look as though the whole pipe work has to be unscrewed and the water drained , if it helps these have metallic covers not sure what make .

What im asking is what do people think has happened from the lever not working for auto and manual and the vlave just not doing anything has the motor seized or something else .

 

[CBW]

If it is just the motor head, this can be changed by yourself, gas engineer, plumber or electrician. However if you’re having constant issues with a particular brand, than as per @Hugh Jaleak Honeywell have a very good reputation. Myson aren’t too bad, just unserviceable.

You have no resistance in the lever, it would suggest to me that something has failed. What you might be able to try is, turn the power off at the spur, and find out if this releases anything in the valve, and then turn the power back on.

 

[jeff the gasman]

Just swap the synchron motor in the actuator. They fail for fun. Buy a Drayton one from your local Wolseley merchant as they are original equipment and less likely to fail.

 

[Harry Bloomfield]

Can i ask plz because all the time we have had this system these valves are a REAL PAIN IN THE ARSE , i know they do some work but jesus there forever packing up and so many issues with them i once took it off and kept the valve perm open with some pliers one winter ( i know not a good idea but so fed up with them ) .

They are all unreliable, a contant source of trouble the actuators. The most problematical ones are the spring return ones, because they are under constant stress from the spring. If you can find a compatable one, for your system, look at what are called the MOMO type valve. No spring involved, the motor just turns the valve in one direction and stops in the correct position. Swapping to that type, involves swapping both actuator and valve as a unit.

 

[Fast_Muchly]

Just to mention the valves are honeywell 4043h , and its lasted all of 13 months ...............rubbish .

 

[CBW]

Just to mention the valves are honeywell 4043h , and its lasted all of 13 months ...............rubbish .

Genuine Honeywell or Amazon? I believe some aren’t genuine according to some reviews?

 

[jeff the gasman]

Lots of fake synchron Motors out there. Drayton are good Motors.

 

[Harry Bloomfield]

I have only had one motor failure here, in 40 years - usual problem is the actuator seizing due to the stress they are under from the spring, or micro-switches failing. Valve itself jamming - never, but then my system is well maintained and clean. The valve has always been perfectly free. even after 40 years and several actuators.

 

[dilalio]

It's an electromechanical part that does a lot of work.

 

[oldbuffer]

From memory, you can't use a MOMO valve on an unvented cylinder, because they don't fail to closed.