No hot water after recent plumber visit

[1SJC]

Hello,

I've recently had a plumber complete a fair amount of work laying some new copper pipes to supply water to our garage, moving the location of our stop tap, new kitchen & utility drainage, and the hanging of a couple of radiators.

The plumber was here Friday for 8-ish hours, during which time the system was drained.

Subsequently, we've noticed over the weekend that there's been no hot water and have had to use the immersion heater to get any hot water.

We have experienced similar issues in the past when plumbers have been to carry out work, and it's my understanding that the Honeywell Motorized valves can often get stuck/give up working when the water has been drained from the system. And so as a result, we'd like to understand what's failing in the system so we can replace it ourselves instead of having to pay for the plumber to come back and fix the issue.

We have a Drayton Wiser Thermostat control kit and a gravity-fed system. If we boost the water, the boiler receives the call for hot water and shows a working/burning code, so we believe it must be one of the motorized valves that have failed once again.

I've attached a photo of our hot water tank, and there appears to be 2 motorized valves. However, I'm not sure which one I need to change possibly. The central heating is working as normal, and radiators get hot when requested, so I don't want to interfere with that working as normal if I can help it.

Is it possible to tell from the photo which one I should look to replace?

https://imgur.com/P3dGKp9

Thanks for your help.

 

[ianmcd]

The top one in your pic is the HW zone valve, but I wouldnt replace it just because the system was drained, slect HW on and feel the small lever on the RH side of the valve , when you push the lever up is there resistance ?

 

[1SJC]

The top one in your pic is the HW zone valve, but I wouldnt replace it just because the system was drained, slect HW on and feel the small lever on the RH side of the valve , when you push the lever up is there resistance ?

I tried the lever when the HW was off and there was resistance. Now it's on, the unit is hot to the touch and there isn't any resistance.

 

[ianmcd]

Then the zone valve is working correctly,, just before the xone valve to the right there is a small vertical legth of insulation, remove that and there will be a manual air vent at the top, crack that open till water comes out and then the HW should work

 

[1SJC]

Then the zone valve is working correctly,, just before the xone valve to the right there is a small vertical legth of insulation, remove that and there will be a manual air vent at the top, crack that open till water comes out and then the HW should work

I've given that a go. There was a small amount of air but not masses. I'll see whether the water gets hot now.

One of the first plumbers did install a pump with a couple of silver values that you'll see at the top of this photo and when we had a similar problem previously, he recommended turning the dials with a screwdriver just a crack until water starts coming out (much like you recommended for the vertical length). However, if I turn the dial on either no water comes out like it has done previously.

https://imgur.com/ND2JX5r

 

[ianmcd]

Is that a pump for a power shower ? Hint attach your pics using the attach files button on the bottom LH side of your post , makes it easier for us to see them, , try turning both ch and hw off , the manually open the HW Zone valve and latch it, you will see a small grove to latch it, with that open and everything off, do you get more water from the air vent ?

 

[1SJC]

Is that a pump for a power shower ? Hint attach your pics using the attach files button on the bottom LH side of your post , makes it easier for us to see them, , try turning both ch and hw off , the manually open the HW Zone valve and latch it, you will see a small grove to latch it, with that open and everything off, do you get more water from the air vent ?

It's a pump for all the hot water in the house, taps, shower, etc.


With both CH and HW off, and opening the air vent there was more air before water did eventually come out at the top.

 

[ianmcd]

With both CH and HW off, and opening the air vent there was more air before water did eventually come out at the top.

Read the whole post, you have to also manually open the HW zone valve and latch it open, as you bleed it, that is the whole function of that lever, when you dont latch the valves and try to re-fill the system you will get airlocks

 

[1SJC]

Read the whole post, you have to also manually open the HW zone valve and latch it open, as you bleed it, that is the whole function of that lever, when you dont latch the valves and try to re-fill the system you will get airlocks

Sorry Ian, I did actually do that but just didn't type that I did.

The release of air and then a little bit of water was as a result of me opening the latch to manual and catching it on the top lip, and then unscrewing the air valve with both the CH and HW off as your reply instructed.

 

[Johntheo5]

If a sealed system what is the boiler pressure, should be ~ 1.5bar cold and not less than 1.0bar, if a open vented system check for water in the Feed & expansion (small) Tank in the attic.

Can you boost both the HW and the CH and see if the rads start heating (and the HW).

 

[CBW]

Hello,

I've recently had a plumber complete a fair amount of work laying some new copper pipes to supply water to our garage, moving the location of our stop tap, new kitchen & utility drainage, and the hanging of a couple of radiators.

The plumber was here Friday for 8-ish hours, during which time the system was drained.

Subsequently, we've noticed over the weekend that there's been no hot water and have had to use the immersion heater to get any hot water.

What did your plumber say when you called them to come and rectify the issue?

 

[ianmcd]

If a sealed system what is the boiler pressure, should be ~ 1.5bar cold and not less than 1.0bar, if a open vented system check for water in the Feed & expansion (small) Tank in the attic.

Can you boost both the HW and the CH and see if the rads start heating (and the HW).

It is open vent and the CH is working ,, read post #1

 

[mcprinter]

Not a plumber
I think I had the same problem after partial draining the system and fitting a new rad.
Ended up with an airlock in the HW coil inside the tank.

Fixed with help from the guys on here

No hot water after radiator change

Replaced an upstairs radiator yesterday. Partially drained the system, modified the pipework, refilled and check for leaks. All good. Run the HW 30 mins in the morning and again in evening. Noticed not much HW yesterday evening and none this morning. Conventional boiler (old Ideal Elan) with...

www.diynot.com

 

[Madrab]

TBH, the plumbers are the ones that should be sorting this for you. I am amazed at the number of people I see that have had work done like this and are left with one or both systems not working properly,. What do these 'plumbers' think about when they do work and are about to leave the client when they have completed the job, just open up the filling loop, re-pressurise or re-fill the gravity system and then just walk away.

Where's the checks and tests to ensure everything is as it should be and everything works and the mention of, any probs give us a shout and I'll be over to have a look at it??

 

[dilalio]

Whole point of manual lock offs on MVs is to facilitate draining and refilling of the system.

If your whole hot water system is pumped you need to ensure there is water at the pump inlet. Is there?

Sounds like you have a system full of air locks.