Strange zone valve and pump behaviour..

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dpravo
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Strange zone valve and pump behaviour..

Post by dpravo »

I have an S plan system and over the last few days i've noticed strange behaviour which I hope someone can help diagnose..

When the hot water comes on (typically on a timer), the h/w zone valve opens, the pump starts and then the boiler fires up.. after some time, with the hot water still 'on', the zone valve closes and the pump turns off. Then after some more time the zone valve reopens, the pump starts and the boiler fires up.. then the cycle just repeats.

What used to happen was that once the hot water came on, the zone valve would stay open and the pump would run the entire time the h/w was on.. with the boiler firing up intermittently to keep the hot water cylinder hot.

Can anyone advise what might be causing this change if behaviour? Thanks in advance for any advice!

To add to this ( and I hope its not related ) i did have a replacement pump fitted a few weeks back.
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Someone-Else
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Strange zone valve and pump behaviour..

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dpravo wrote: Thu Sep 26, 2024 8:40 pmi did have a replacement pump fitted a few weeks back.
............and when did this problem start? and who changed the pump? (Plumber, heating bod, you?)
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dpravo
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Strange zone valve and pump behaviour..

Post by dpravo »

The problem started about 2 weeks after the pump was changed, by my usual plumber/heating engineer who has been working on my house for years.
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Someone-Else
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Strange zone valve and pump behaviour..

Post by Someone-Else »

I would suggest you ask him, did he do ANYTHING else?
Above are my opinions Below is my signature.

Would you hit a nail with a shoe because you don't have a hammer? of course not, then why work on anything electrical without a means of testing Click Here to buy a "tester" just because it works, does NOT mean it is safe.

:mrgreen: If gloom had a voice, it would be me.

:idea1: Click Here for a video how to add/change pictures


Inept people use the QUOTE BUTTON instead of the QUICK REPLY section :-)
dpravo
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Strange zone valve and pump behaviour..

Post by dpravo »

Great suggestion, thanks. Yes he also replaced a degraded o-ring on a Magnaclean filter.
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